I don't believe the husband's pathetic excuse of "she laughed at him", I think he had "bottled" up lifelong resentment of his wife's successful career and he was jealous. We don't know anything about him but many husbands resent their wife's successful career and feel it is belittling having a successful wife, (making him feel inferior). I think he is a jealous husband and the cruise ship just happened to enclose them closer together than they normally live, (they can get further apart and keep out of each other's way at home) - bringing a lifetime's resentment to an explosive climax. He had to bash her head in quite a few times. So it was really quite a violent and brutal attack. Witnesses said blood was splattered on every surface everywhere, after which all he could think about was himself....(his life was over according to him). That is how he thinks. JMOO