I've been reading the replies, let me clarify.
* dd was doing hw when she said she was tired, he thought it to be funny to put her in a cold shower for a few seconds. He was not disciplining nor was she misbehaving.
* she was crying and telling him to stop
* If she was having fun I wouldn't have intervened but clearly she wasn't
* I tried TALKING to him after, he got upset, it escalated into an argument, he left, came home at 1 am
* I did not say to him "I hate you". I said it here
* I did not put him out