Prosecutors have a lead against someone holding Ukrainian citizenship. That doesn’t say anything more than that someone with Ukrainian citizenship was involved, in particular it doesn’t say that he’s not a Russian operative. Or Polish, for that matter, the Poles were uncharacteristically uncooperative.

In any case it’s not like Germany would be mad it’s the wheels of justice churning as usual. Heck at this point I haven’t ruled out that it was a German operation. The whole yacht theory is in general on shaky ground because one does not just lower some sea mines with a yacht. Or smuggle them to a Polish port. etc., etc.