Is a drunk kiss considered cheating?

my boyfriend of 9 months went out 3 weekends ago and had a lot to drink. He takes depakote 500 (epelepisy medicine) and becomes a different person when he drinks alcohol. His personality changes completely. He was at a friends house and a woman came on to him and kissed him in the middle of a conversation they were having. the kiss only lasted a few seconds before she moved down to his neck and began to give him a hickey. He said - at the time she was doing this... all he could remember was his head went fell back and his eyes rolled in the back of his head. When she moved to the other side of his neck, he came to and told her to stop and that he can't do this. When he realized what he had done, he put a stop to it. His reaction time is alot slower when he is as drunk. He also has no control over any situation when he's drunk. He realizes drinking is a major problem and in order to make our relationship work he can't drink anymore. So do i give him a chance?