She might have entered the room by mistake and he might have gone out of the shower unaware of her presence (It happened to me already). In that case, French regular behavior would be for both sides to appologies with embarrassment (sorry to break your romantic ideas about France
).
Anyway, in US, my first move would have been to call room service right away to complain about that maid. Just covering as I consider a good part of american women to be nuts.
As I was in college, one of my friend asked a cop who had come to make a lecture how he could prevent himself from being charged with rape if he had occasional sex with an american woman. The cop simply answered him that his best option was to tape it (my friend married a Japanese). For my part, I chose to date Japanese, eastern europeans, south americans, Thai... Anyway, in each party as soon as you were known to be french, you would see a full line of football quarterback being formed around each american girl (damn has it been a pain to be french in an american college
).
Overeaction could be an option but, so far, I have no reason to doubt her more than I doubt him.