Only thing I couldnt take is everything is blamed on Pat!!!

I really liked the movie but I think pat was given a raw deal here. I mean his delusions were not unfounded. Do I think he should of beat the guy half to death? No but I feel like a little understanding is due here. Also his wife didnt even have the common decency to cheat on him at the other guys house or in a hotel. It is just like she gets off scott free. We dont get to much background but even if she was unhappy at least try and make it a secret.