The whole point of having these conventions is to provide some unification of law. Recent US jurdgements have broadened the term "accident" and I believe rightly the UK has followed the traditional stance. But this effects the concept of the systems, and Montreal (the new convention) has neither cleared up the existing problem with the concept of accident, but has also introduced the fifth jurisdiction - enabling claimants to bring an action under their own laws (not literally their own conept of law but their own national law). Now that being said, Pax A and Pax B both bring a claim, Pax A fails, Pax B succeeds, same grounds, same facts, same law, different result. Hmmm fairness, justice, unification? This isnt just about DVT this is about every incident that could be interpreted as an accident from turbulence to food poisoning, to sexual harassement by other passengers. At least thats my twopeneth worth. Merry Christmas.