MVF3 APS & Ors v Bestnet Europe Ltd & Ors

The addition of LDPE to a polymer matrix otherwise consisting of pure HDPE would generally be expected to increase deltamethrin migration, with higher percentages having a greater effect. That general expectation does not establish that the small quantities used in a particular formulation have a significant effect. The evidential question must be assessed by reference to the relevant experimental data and formulation. Where the evidence does not permit comparison between LDPE and other additives, no conclusion about their relative effects can be drawn. A remitted factual inquiry does not, without more, reopen other findings or make previously relevant technical evidence useless.

The claimants had obtained judgment for breach of confidence arising from misuse of trade secrets. The defendants appealed and sought to rely on later-disclosed technical material, including a patent application and experimental documents. On 24 November 2010 the Court of Appeal remitted three factual questions to the Chancery Division under CPR r. 52.10(2)(b): the effect of adding LDPE on deltamethrin migration, its comparative effect against specified additives, and whether the Fence results remained useful. The judgment determined those questions while leaving the effect of the remission and any issue estoppel for the Court of Appeal.

1. Scope of the remission. The court had not been directed to decide whether the documents should have been disclosed earlier. It assumed, without deciding, that the Court of Appeal’s order permitted reconsideration of the disputed factual conclusion in light of the new evidence. The original judgment and order remained res judicata unless and until the appeal succeeded.
2. Evidence. The expert evidence was admissible to assist in understanding the documents and experimental data. The court gave little weight to Professor Stevens’ critical-level theory because he resiled from it in cross-examination and the underlying analysis contained errors. No adverse inference arose from the claimants’ failure to call factual witnesses: the issue was what the experimental data objectively established.
3. LDPE. In general terms, adding LDPE to pure HDPE would be expected to increase deltamethrin migration. However, the evidence did not show that the quantities used by the defendants had a significant effect. The R12 trial did not support that conclusion, and the later evidence did not justify revision of the earlier finding.
4. Comparative effects. [ADDITIVE A] operated as a migration enhancer and [ADDITIVE C] as a migration inhibitor. The evidence did not permit a reliable comparison between the effect of LDPE and the effects of [ADDITIVE A], [ADDITIVE B] and [ADDITIVE C]. The proposed critical level of LDPE was not established.
5. Disposition. The Fence results were not rendered useless for formulating the defendants’ product. The three remitted questions were answered: general LDPE effect but no significant proven effect at the defendants’ quantities; specified additive effects as stated above; and no.

• Court of Appeal: On 24 November 2010, remitted three factual questions to the Chancery Division under CPR r. 52.10(2)(b), with the substantive appeal adjourned pending determination.
• High Court (Chancery Division): Determined the remitted questions and declined to revise the earlier findings.