Patents Court Practice - SafeStand Ltd v Weston Homes Plc

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Jane Lambert

Patents Court (Campbell Forsyth) Safestand Ltd v Weston Homes Plc and others [2023] EWHC 1098 (Pat) (10 May 2023)

A fundamental principle of civil litigation in England and Wales is that each party discloses to the other(s) any and all documents in his or her possession, custody or control that relate(s) to an issue in the proceedings.  An important exception is that documents that are prepared for the purpose of litigation do not have to be disclosed because they are protected by legal professional privilege.  The concept of "legal professional privilege" is explained conveniently by this anonymous article dated 30 Aug 2022 on the Law Society website.

Legal Professional Privilege and Experiments

In patent proceedings, parties often carry out experiments to prove or disprove facts that may be in issue.  Those experiments are covered by legal professional privilege and there is no need for the party carrying them out to disclose them to the other side so long as they are not referred to.  However, if the party that carried out the experiment wishes to refer to the experiment at trial he or she waives his or her legal professional privilege.  

An experiment that produces a favourable result is often the culmination of earlier experiments which Mr Justice Pumfrey called "part of the 'workup' or preliminary investigation leading to the experiment" at para [1] of his judgment in Mayne Pharma Pty Ltd and another v Debiopharm SA and another [2006] EWHC 164 (Pat) (10 Febr 2006).   These earlier experiments may well produce results that favour one or more of the other parties.  It would be unfair to allow the party seeking permission to use the results of the last of a series of experiments to disclose the results upon which he or she wants to rely but not the other results.  As Mr Justice Mustill said in Nea Karteria Maritime Co v Atlantic & Great Lakes Steamship Corporation [1991] ComLR 138 at139:  "where a party chooses to deploy evidence which would otherwise be privileged the court and the opposition must, in relation to the issue in question, be given the opportunity to satisfy themselves that they have the whole of the material and not merely a fragment."

The Litigation

The issue arose in SafeStand Ltd v Weston Homes Plc and others [2023] EWHC 1098 (Pat)) which was an action by SafeStand Ltd ("SafeStand") for patent and re-registered design infringement.  There was also a counterclaim by Weston Homes Plc and two of its subsidiaries ("Weston") for revocation of the patents, cancellation of the design registrations and a declaration of non-infringement.   

SafeStand makes and sells scaffolding platforms for use in the construction industry.  A photo of its product appears on the SafeStand® Features page of its website.  Readers will note that the platform rests on trestles.  SafeStand is the proprietor of GB2378978A for a Builders' Trestle System and EP(UK)1660738 for Fittings for Builders' Trestles.   It complained that Weston had infringed those patents with their "Kwik Kage System" ("KKS").  Weston denied that the KKS infringed the patents on the ground that it neither consisted of nor included any trestles. 

They put their case as follows in their skeleton argument:

"27. The core points are whether D's Main Frame fitted with Starter Plates is a "builders' trestle" (integer 1A), and whether planks/boards on those devices can be "supported in use to make a platform" (integer 1B). The wording of integer 1A and 1B differs very slightly between the 978 and 738 Patents, but raises substantially the same issue in each case.
28. Put simply, D's case is that its Frames (i.e. Main Frame fitted with Starter Plates) are not builders' trestles, and they are not "builders trestles" that can support planks in use to make a platform. Furthermore, again put simply, Ds' case on equivalents is that its Frames are not functioning in the same way as builders' trestles – stability is achieved by an entirely different mechanism, that is to say by the addition of two cross-braces between all adjacent Frames, thereby connecting them, stabilising them, and fixing the distance between them. Ds say that the stability in the trestle/trestle system is provided by the feet of the trestles (which must have sufficient size and rigidity), and that this is not the case with the D's system."

The Experiments

To supports their argument, Weston conducted the following experiments ("the Experiments"):

"(i) Experiment 1 – A single modified Trestle ("Trestle") compared with a Kwik Kage Frame with Starter Plates ("Frame"), both unweighted.
(ii) Experiment 2: A single Trestle compared with a Frame, both weighted (252 kg). (Experiment2)
(iii) Experiment 3: A three-bay Trestle Platform, a three-bay unbraced Kwik Kage System and a three-bay Kwik Kage System. Each bay was weighted with 252 kg. These systems were as follows:

(a) Trestle Platform – comprising three-bays and four Trestles fitted with removable uprights, front and end handrails (top and bottom), anti-flip brackets and scaffold boards.
(b) Unbraced Kwik Kage System – comprising three bays and four unbraced Kwik Kage Frames fitted with starter plates, removable uprights, front and end handrails (top and bottom), anti-flip brackets and scaffold boards (no cross-braces).
(c) Kwik Kage System – comprising three bays and four frames, (except for the absence of Kickboards) fitted with starter plates, removable uprights, front and end handrails (top and bottom), anti-flip brackets, scaffold boards and six cross-braces."

The Experiments compared aspects of the performance of the standard frame KKS with trestles constructed in accordance with the patents with the trestle top cross member being the same height as the KKS frame cross member.   The purpose of the Experiments was explained by Weston's expert witness at para 442 of his report:

"The tests aimed to quantify differences or similarities in performance of a "Kwik Kage Frame" and Trestle, and a Kwik Kage System and a Trestle Platform, from the initial application of the forces through to the maximum longitudinal force resisted by each item or arrangement in each test. Experiment 3 also included testing of a changed version of the Kwik Kage System with all the cross-braces removed."

The Application

Para 7.1 of the Part 63 Practice Direction requires a party that wants to establish a fact by experimental proof conducted for the purpose of litigation to serve a notice on the other party or parties stating the facts that he or she seeks to establish with full particulars of the experiments proposed to establish those facts.  The party served with that notice then was 21 days to serve a counter-notice on the applicant stating whether or not each such fact is admitted and request the opportunity to inspect a repetition of all or a number of the experiments identified in the notice.  Where a fact is not admitted, the applicant must apply to the court by application notice for permission to rely on the experiments and directions.

Weston served a notice of experiments on SafeStand in accordance with para 7.1 on 22 Nov 2022.   Those companies amended their notice on 14 Feb 2023.  By an application notice dated 14 April 2023, they requested permission to rely on the Experiments as set out within their notice of experiments as amended and reamended ("the ANOE") pursuant to para 7.3 of PD63.   The ANOE states that the Experiments show how much horizontal force needs to be applied to topple the frame/system, and the initial resistance to displacement/movement of the frame/system which are said to indicate steadiness, stability and safety in use.

The Cross-Application

Although it disputed the relevance of the Experiments to the question of whether the KKS was a trestle, SafeStand did not oppose Weston's application.  Instead, it sought specific disclosure of the following documents by an application notice dated 13 March 2023 pursuant to para 18.1 of Practice Direction 57AD and/or the Court's case management powers as preserved by para 20.1:

"1.1 an unredacted copy of Section 1 and Appendix A of the ..... NRFIS Report ... of 18 November 2022;
1.2 a copy of Section 2 of the NRFIS Report and/or any other section that removes redactions relating to non-confidential materials on the kickboard experiments, disclosed to the Claimant in the original Notice of Experiments or otherwise;
1.3 any data provided by the NRFIS in relation to the Experiments described in the NRFIS Report in Section 1 or Appendix A;
1.4 any report or data relating to any experiments or tests carried out to test the longitudinal stability or initial resistance to displacement of the KK 600 Main Frames described in the Re-Amended PPD; and
1.5 any report or data relating to any experiments or tests carried out in respect of the longitudinal stability or initial resistance to displacement of any builders' trestle which is shorter in height that the Trestle described in the Notice of Experiments."

The "NRDIS Report" referred to a report on the experiments that had been carried out on Weston's behalf at the National Research Facility for Infrastructure Sensing ("the NRFIS").   

Weston objected to SafeStand's application for specific disclosure on the grounds that the documents sought by Safestand were privileged and that their disclosure would not be necessary for the just disposal of the action.  They also argued that disclosure would be expensive and disproportionate. 

The Hearing

The application and cross-application came on for hearing before Mr Campbell Forsyth sitting as a deputy judge of the High Court on 20 April 2023. The learned deputy judge handed down his judgment on 10 May 2023. As Weston's application was not opposed, Mr Forsyth allowed those companies to rely on Experiments 1 to 3 to prove the facts in the ANOE at para [28].  Most of the rest of the judgment was concerned with whether he should grant SafeStand's application for specific disclosure and the terms on which he should grant it were he to do so.  It will be seen that he expressed an intention to make an order for specific disclosure.

Specific Disclosure as a Condition for Permission to Rely on the Experiments

SafeStand referred the deputy judge to Mayne Pharma Pty Ltd. in which Mr Justice Pumfrey was willing to declare at para [22] "that any legal professional privilege otherwise attaching to documents relating to workup experiments for the experiment in the notice of experiments has been waived by service of the notice of experiments."  SafeStand argued that permission to rely on experiments in a notice of experiments was conditional upon providing disclosure of the "work up".  Mr Forsyth rejected that contention. The question of any conditional approach to Weston's application was largely irrelevant.  There was no linkage between the two applications.

Jurisdiction

Mr Forsyth considered whether he had jurisdiction to make the order that SafeStand had requested.  The reason he considered that question is that the proceedings had been brought in the Patents Court while the Disclosure Pilot Scheme (PD51U) was in force.  Para 2.4 of that practice direction stated:

"The court will be concerned to ensure that disclosure is directed to the issues in the proceedings and that the scope of disclosure is not wider than is reasonable and proportionate (as defined in paragraph 6.4) in order fairly to resolve those issues,"

The pilot scheme expired on 1 Oct 2022 and was replaced by Practice Direction 57AD which applied to existing as well as new disputes in the Business and Property Courts.  Para 2.4 of PD57AD was identical to para 2.4 of PD51U.

Although Mr Justice Mann had already given directions for disclosure at the case management conference,  Mr Forsyth noted that para 18.1 of PD57AD allowed the court to order specific disclosure even after directions for disclosure had been given. Para 18.2 required the party seeking such an order to satisfy the court that varying the disclosure order would be necessary for the just disposal of the proceedings and also "reasonable and proportionate" as defined in para 6.4. That para provided:

"6.4 In all cases, an order for Extended Disclosure must be reasonable and proportionate having regard to the overriding objective including the following factors—
(1) the nature and complexity of the issues in the proceedings;
(2) the importance of the case, including any non-monetary relief sought;
(3) the likelihood of documents existing that will have probative value in supporting or undermining a party's claim or defence;
(4) the number of documents involved;
(5) the ease and expense of searching for and retrieval of any particular document (taking into account any limitations on the information available and on the likely accuracy of any costs estimates);
(6) the financial position of each party; and
(7) the need to ensure the case is dealt with expeditiously, fairly and at a proportionate cost."

Referring to  White Winston Select Asset Funds LLC v Mahon [2019] EWHC 1014 (Ch) where Mr Edwin Johnson QC had ordered specific disclosure under his case management powers, Mr Forsyth also held that he had jurisdiction to order specific disclosure pursuant to CPR Part 3.1 (2) (m).   

He was therefore satisfied that he had jurisdiction to make the order notwithstanding Mr Justice Mann's directions either under CPR 18.1 or CPR 3.1. 

Waiver of Privilege

SafeStand based its application for specific disclosure on Mr Justice Pumfrey's decision in Mayne Pharma.  It contended that the ANOE constituted a waiver of privilege by Weston and that it was therefore entitled to see the work up.  

Mr Forsyth said at para [45] of his judgment that the relevant authorities and principles applicable to SafeStand's application had been set out and considered in considerable detail by Mr Daniel Alexander QC in Magnesium Elektron Limited v Neo Chemicals & Oxides (Europe) Ltd (No.2) [2017] EWHC 2957 (Pat) between paras [37] to [82] of his judgment in that case.  Mr Forsyth reproduced those paragraphs and annexed them to his own judgment.   They dealt with the relevant principles of legal privilege, waiver of privilege, and disclosure relating to experiments in patent cases such as Mayne Pharma.  In those paragraphs, Mr Alexander quoted from the judgments on which he relied and discussed how the principles that he discerned from those cases were to be applied.  Mr Forsyth adopted Mr Alexander's analysis.

Mr Forsyth also referred to paras [111] and [114] of the Court of Appeal's judgment in Civil Aviation Authority v Jet2.Com Ltd, R. (on the Application of) [2020] EWCA Civ 35 on the relevant principles on collateral waiver of privilege in respect of a set of documents otherwise non-disclosable, as the result of the voluntary disclosure of other privileged documents:

"[11]. The relevant principles are uncontroversial. Although the voluntary disclosure of a privileged document may result in the waiver of privilege in other material, it does not necessarily have the result that privilege is waived in all documents of the same category or all documents relating to all issues which the disclosed document touches. However, voluntary disclosure cannot be made in such a partial or selective manner that unfairness or misunderstanding may result (Paragon Finance plc v Freshfields [1999] 1 WLR 1183 at page 1188D per Lord Bingham CJ).
[112]. Collateral waiver of privilege allows for documents and other material that would otherwise be non-disclosable on public interest grounds, to be required to be disclosed even though the individual with the right to withhold disclosure objects. The courts have therefore imposed certain constraints on collateral waiver.
[113] The starting point is to ascertain "the issue in relation to which the [voluntarily disclosed material] has been deployed", known as the "transaction test" (General Accident Fire and Life Assurance Corporation Limited v Tanter [1984] 1 WLR 100 at 113D per Hobhouse J), waiver being limited to documents relating to that "transaction" subject to the overriding requirement for fairness. The "transaction" is not the same as the subject matter of the disclosed document or communication, and waiver does not apply to all documents which could be described as "relevant" to the issue, in the usual, Peruvian Guano sense of the term as used in disclosure (Compagnie Financière et Commerciale du Pacifique v Peruvian Guano Company (1882) 11 QBD 35).
[114]. … The purpose of the voluntary disclosure, which has prompted the contention that privilege in other material has been collaterally waived, is therefore an important consideration in the assessment of what constitutes the relevant "transaction" (see also Dore v Leicestershire County Council [2010] EWHC 34 (Ch) at [18]-[19] also per Mann J)."

Mr Forsyth said in para [47] that the scope of a waiver of privilege is a question of fact to be determined in each case.  He began his analysis by quoting para [83] of Mr Alexander's judgment in Magnesium Electron:

"Patent cases are no different to any other cases in that documents recording activity undertaken for the purpose of litigation attract privilege. Until they are deployed, they remain privileged. Once deployed, the question as to the extent to which, if at all, the effect of doing so is also to waive privilege in any other documents or material. …. In patent cases, as in any other, the opposite party and the court must have the opportunity of satisfying themselves that 'what the party has chosen to release from privilege represents the whole of the material relevant to the issue in question'".

Mr Forsyth summarized the problem as how to define the boundaries of the material that is relevant to the issue put in question.

He noted that Mr Alexander had reviewed Mr Justice Pumfrey's decision in Mayne Pharma between paras [84] and [88] of his judgment.  He quoted para [15] of Mr Justice Pumfrey's judgment:

"Experimental evidence is intended to prove a degree of objective confirmation or corroboration of the subjective views of the experts. ….. It may provide, and from time to time does provide, a fixed point against which the experts may themselves be assessed. It is the one place in litigation of this class where an appeal to scientific technique is directly made. It is employed because it trumps the experts, however cogent their views may be."

In Mr Forsyth's view, Mr Justice Pumfrey was making a statement here of general application, which Mr Forsuth adopted, about the nature of this type of evidence. For example, as a consequence, 'work up' experiments should not be limited to preliminary investigations leading to the experiment relied upon but could encompass other related litigation experiments which provide materially relevant contextual information on the experiments relied upon. It was an issue that distinguished cases relying on experiments as evidence proving facts from other cases.  However, he referred to the following paragraph of Mr Justice Pumfrey's judgment that he was reflecting "a need to reveal the full story rather than just its culmination" and did "not wish to be taken to be expressing a view in any other context at all."

Mr Forsyth noted that Mr Alexander had identified some of the difficulties that can arise in the practical application of assessing the boundaries of workup experiments in cases with experiments "which have multiple components or stages and may be run multiple times in different ways." between paras [89] and [91] of his judgment in Magnesium Electron.  At para [90] Mr Alexander said:

" In my view, in the light of the restrictive approach from the general authorities and in the light of Mayne Pharma itself, the disclosure required to be given does not extend beyond materials recording preliminary investigation leading to the particular experiment which is deployed in evidence and does not extend to other parts of an overall experimental programme even if the design of the experiment in question may have drawn on earlier experiments. That narrow approach is consistent with the authorities above and which treat implied waiver of privilege restrictively in the general law."

Although Mr Forsyth agreed that there should be a careful restrictive approach to disclosure where there has been a waiver of privilege, he did not believe that such an approach fettered the discretion of the court or required patent cases to be treated differently from other cases involving a waiver of privilege. The principles that the courts had developed to address issues of reliance on partial disclosure were of general application.

Mr Forsyth saw that Mr Alexander had divided waiver of privilege in patent claims into two categories. The first was a specific situation where experiments are deployed on the basis they would inevitably be selected and undertaken as described and would invariably give the results identified. The second was where the repeatability of an experiment and any significant variation in result meant that it was critical to have information about that issue and any failure to provide all relevant data set could lead to unfairness. He added that what is meant by unfairness, by 'the experiment' and where the boundary lies on "completeness of data" were issues in SafeStand's application,

Mr Alexander quoted the following passage from Matthews & Malek on Disclosure 5th edition:

"The general rule is that:
Where a person is deploying in court material which would otherwise be privileged, the opposite party and the court must have the opportunity of satisfying themselves that what the party has chosen to release from privilege represents the whole of the material relevant to the issue in question. To allow an individual item to be plucked out of context would be to risk injustice through its real weight or meaning being misunderstood."

Weston's Disclosure

In party-to-party correspondence arising out of the application, Weston supplied: 

(i) confirmation that there had been no runs (experiments using an identical experimental protocol), work-ups test runs and or trials (with or without limitation) in relation to any of the Experiments relied on in the ANOE,
(ii) a redacted copy of the NRIFS Report from the Initial Experiments (Initial NRFIS Report) and
(iii) Excel spreadsheets with corresponding graphs in relation to experiments from the initial experiments to the extent they related to the Experiments in the ANOE.

Parties' Contentions

SafeStand's position was that this was a case of selective disclosure by Weston. The ANOE was a partial disclosure of the evidence of the stability of the parties' scaffold platforms. Relying on the redacted RFIS Report and the 23 tests listed in a table in the Report, SafeStand believed that there was a wider body of evidence of tests involving the application of horizontal loads to different configurations of the parties' scaffold platforms. As the table had a column for the height of the frame, it was likely to record variable heights and not just the standard frame KKS.  It was therefore possible for the SS 600 as well as the standard frame platforms to be tested.  Relying on geometry SafeStand's expert believed that "the shorter KK600 Frames would be more stable than the taller Standard frames and the trestles" by a considerable margin. SafeStand concluded that if such experiments existed and showed that result then the non-infringement argument would fail.

Referring to their own expert evidence Weston challenged SafeStand's analysis and denied that they relied on the Experiments in relation to KK 600.  They contended that the Experiments were separate from experiments on other issues,   As Weston relied only on the Experiments in relation to infringement and the standard frame KKS there was no need to disclose any other experiments.

Assessment

The deputy judge directed himself as follows at para [78]:

"In order to assess this application for disclosure it is necessary to first decide what, if any, waiver of privilege has taken place as a result of the Defendants' reliance on its ANOE. This is a case of voluntary disclosure and the court is therefore concerned with implied or consequential waiver of privilege. In these circumstances, it is important to take a 'relatively cautious and restrictive approach' to waiver of privilege in documents not deployed and that any waiver of privilege in such material should only be to the limited extent necessary. In order to assess the boundaries of any waiver of privilege I need to consider the issue in question the ANOE is deployed to address, also sometimes considered as identifying the underlying 'transaction'. This requires considering in the context of a case what the Defendants are seeking to disclose and what implied or express representations are relied on based on the facts it is said to evidence. This is a fact sensitive exercise."

His starting point was the question, "What is a 'trestle?'" in the context of integers 1A and 1B of the above-mentioned patents. That question was an important issue in the case. Weston's expert had given the following opinion on the meaning of the word as it would be understood by a person skilled in the art:

"the skilled person would understand that a builder's trestle is a self-standing support for a platform which will (with other trestles) support the platform in normal use without the need for any additional structural support."

As Weston had wanted to use the Experiments to show that the standard frame KKS were not trestles, they submitted that any other experiments that may have been conducted for any other purpose would have been irrelevant. 

In Mr Forsyth's view, the purpose of deploying the ANOE was to prove that trestles have greater longitudinal stability than Weston's products. The difference in stability was relevant to the point of construction. It followed that any other associated experiments which dealt with the consistency of the relative stability of the triangular support trestles and Weston's products would be part of the purpose of deploying the ANOE. To establish the technical meaning of 'trestle' the difference in longitudinal stability would need to be measured consistently in different conditions. Evidence on the relative differences of longitudinal stability in experiments with conditions varying the frame size would be relevant to the proposition asserted by Weston's expert on the technical meaning of the term 'trestle',  It would therefore be relevant to the construction of the claims and the question of infringement. In the circumstances, the disclosure proposed by Weston could risk a misunderstanding of the evidence and thus be a partial or selective disclosure.

In considering this point the deputy judge was mindful of the dicta of Mr Justice Pumfrey in Mayne Pharma on the particular role of objective experiment evidence. Experimental evidence can be an 'anchor' in uncertain waters.  Its influence can be critical.  Consequently, the partial disclosure of experiments which were part of the same transaction or went to the same issue could lead to injustice.

Mr Forsyth considered other ways in which SafeStand could ascertain the information that might have been revealed by the other experiments. SafeStabd could carry out its own experiments but they would be expensive. It could ask Weston's expert or seek further information under CPR Part 18. None of those remedies would be as effective as specific disclosure. The deputy judge held at [85] that Weston's reliance on the ANOE was an implicit or consequential waiver of privilege in relation to any experiments dealing with the relative longitudinal stability of the KKS and that of the patented invention,

Between paras [85] and [96] of his judgment, Mr Forsyth addressed Weston's alternative argument that the ANOE was limited to the question of infringement of the standard frame KKS and that all experiments on all other issues remained privileged.  As the Experiments measured the longitudinal loads that the KKS and patented structures could bear they were effectively doing the same work as would have to be done to ascertain what constituted a trestle.   As the deputy judge put it at [87], "once I had the opportunity to consider all the relevant materials the issue seems to come back to effectively the same point on the consistent application of the technical meaning of the term 'trestle' in the context of the claims of the Trestle Patents." He, therefore, concluded at para [82] that Weston's reliance on the ANOE was an implicit or consequential waiver of privilege in the material in which disclosure was sought from any experiments dealing with relative longitudinal stability of the PPD products (or variants) and the Trestle.  Mr Forsyth arrived at that conclusion in relation to non-infringement under both a normal construction of the claims or the doctrine of equivalence because Weston's case on non-infringement by equivalents depended on the meaning of 'trestle'.

He said at para [96]: "I regard the deployment of the ANOE by the Defendants as an implicit or consequential waiver of privilege in any experiments conducted and recorded in the NRFIS Report which go to the relative longitudinal stability of the Trestle and the Defendants' products in issue in the PPD (or variants of those, for example height of the Frame)."

In relation to SafeStand's application for "a copy of Section 2 of the NRFIS Report and/or any other section that removes redactions relating to non-confidential materials on the kickboard experiments, disclosed to the Claimant in the original Notice of Experiments or otherwise" the judge noted that Weston had voluntarily disclosed a redacted copy of the NRFIS Report. Para 16 of PD57AD provides:

"A party may redact a part or parts of a document on the ground that the redacted data comprises data that is—
(1) irrelevant to any issue in the proceedings, and confidential; or
(2) privileged."

Some of the redactions applied to experiments in the original notice which were no longer relied upon and were therefore irrelevant.  As for the other redactions, Weston argued that the exercise was disproportionate and unnecessary.  Mr Forsyth rejected that contention.  The document was 15 pages long and there were 2 pages of redactions.  The effort required to remove them was minimal.  It was not alleged that the redacted material or much of it was confidential. Based on the proportionality of this matter in this context and the need to comply with the court rules the deputy judge decided that Weston should provide a compliant version of the NRFIS Report without redactions of material that was irrelevant and not confidential.  He also required Weston to provide an appropriately detailed explanation of any privileged sections remaining in the NRFIS report.

Conclusion

The last paragraph of the judgment indicated that there was to be a consequential hearing to determine the form of the order.  If such a hearing has taken place the transcript has not yet been published.   Anyone wishing to discuss this article may call me during office hours or send me a message through my contact form.