Update 20 October 2020 for additional analysis see here.
I reported earlier on the jurisdictional issues in BNP Paribas SA v Trattamento Rifiuti Metropolitani SPA  EWHC 2436 (Comm) . In current judgment the issue of interest to the blog is the possibility of res judicata /issue estoppel on the substance of the claim as a result of arguments made in the jurisdictional challenge.
The issue is an important one given the English (potentially other States’) courts’ inclusion of a ‘serious issue to be tried’ test in which the judge has to decide to ‘much the better of the argument’ standard at the jurisdictional gateway level. While aimed at determining jurisdiction, this inevitably engages with some discussion on the merits.
Cockerill J is justifiably cautious in accepting much estoppel, given the clear separation between jurisdictional and substantial discussions. I do feel she might have pointed out the relevance of the case being heard under Brussels Ia rules as opposed to residual English rules. Under the former, a certain amount of merits engagement may be required for some jurisdictional gateways as discussed repeatedly on the blog (and in the jurisdictional rulings there was clearly a lot of engagement with the facts, to establish Article 25 consent for choice of court). But there can certainly not be a ‘serious issue to be tried’ condition for the substance of the case, in the jurisdictional gateways of BIa (summary dismissal proceedings are an entirely different matter).