How is it an example of European governments preventing American weapons from being sold? Are you saying the Finns unilaterally decided that Turkey can't have F-35s, even if the USA wants to sell F-35s to them?
And, of course, the other side of that coin: weapons export regulation is Europe is not something that is meant to actually prevent weapons export. Rather it is used like a company policy: it makes sure everyone regularly has to give the government something they want.
Which is, to put it mildly, not how politicians present those laws.
Look at the political pressure the USA puts on ASML in the Netherlands to prevent them from selling certain products to China because those machines contain some American parts.
The question is explicitly when the reverse has happened, not some general info about European weapon exports or legislation.