I am not for ruining a guys life and it won't be ruined over a single tweet. But if his employer chooses to part ways then he has to accept the consequences and move on. People get fired all the tie for stupid stuff they post on social media. Business's, big or small don't want to be associated with jerks like him and they have that choice. He will be fine, hopefully lesson learned. Remember, he did this the day after the game, not as an emotional reaction.
Besides, "normal" folks don't wish death on others because of a game.