You are correct, the term 'French attack' was inaccurate, but I am not sure what the correct term would be for the level of damage done to the place, it sounds like more than just carelessness.
While I do, in general , think the French were responsible for being there in the first place, I don't think the currrent evidence is enough to prove an atrocity, much less pin the guilt on any individuals.
regards,
Susan