It's not "ultra sensitive", it's a cultural thing. For american readers, you would have warnings for images of nudity, and for european readers warnings for images of violence.

In the case of the UK, they rounded up every German and Austrian citizen. No matter if you were just arriving or had been living in the UK for years/decades. People who were organizing opposition to the Nazis from the UK for five years already were interned. Didnt last long for most of them, but still pretty stupid.

Investigation found he had credible reasons to believe she was of legal age. So I'd say it's a similar Level to the crime he was found guilty of.