Is stronglight european or chinese? I they're european I'm 99% sure they'd be responsible under the european laws as well.
European laws? That means 25 different legal systems, codes and sets of case histories and legal precedents. For the EU alone, then you have Switzerland and Norway too. On the matter of legal stuff, I'm no lawyer but from experience with motorbike parts, if they fail you have to prove you were in no way responsible for the failure, they will claim you could be negligent too, unless you can prove
beyond reasonable doubt that you used the recommended tools in the recommended manner to the recommended torque settings and then used the parts and the motorbike in the recommended manner and maintained it in the recommended manner etc
Anyway, this is WW, not globalcompensation.com so continue with the build news Rich...