Unfortunately paul00's advice regarding Trafi's decision is incorrect. Under Finnish law, Trafi does not have the power or jurisdiction to issue decisions regarding EU261 compensation that would be compelling on Finnair. Trafi can only issue recommendations. This also applies to KRIL.

If one wants to get an enforceable ruling, the only possibility is to sue Finnair before a the District Court of Vantaa (where Finnair's headquarters are) or Helsinki (where Finnair is domiciled). Other courts (even abroad) may also have jurisdiction as well depending on the case.

However, I agree with paul00 that the technical problem does not constitute a hidden manufacturing defect, i.e. the Amstgericht Erding has applied the directive erroneously. Regardless of the outcome of the German case, it is not legally binding in Finland. Similarly, a Finnish District Court judgment regarding another passenger flying on the same flight would not be binding.