So he signs the will over....that heavily implies he suspected his wife after the first incident. And he still ate/drank shit she prepared?? I know there are plenty of other things one should get hung up on here before that but what the hell....

Why not? His life is over regardless, whether through divorce or rightfully killing the traitorous whore anything he did would be his death. The best thing he could have done would have been a murder followed by becoming an anti-woman and anti immigration martyr by going on a shooting spree until the cops kill him.