Is it confirmed, that it was intentional?

That is his defence:

"Having read many books throughout his career, he may have “assimilated” them and “not always consciously” used them in his own writing, he said."

I have never published anything in academic context, but I did write a lot and I often found that phrases of the same topic I read before creep into my own writing, so I could see this happening to me without intention.

"the plagiarism report shows that he was rephrasing all of the sentences rather than copying verbatim"

On the other hand, this is in fact the standard defence when someone is accused of plagiarism. But sometimes it might actually be correct? (No idea here, my french ain't good enough either)

In general the reaction seems out of proportion to me, I much rather would like to have focus on actual fraud in science.

I sometimes read this blog for example and there seem to be other things going on with less attention.

https://forbetterscience.com/