Who is guilty?

A man found his wife with another man in his bedroom. Instead of shouting or beating both of them he just went back to the sitting room. He switched on Television and started watching some gospel videos. The wife and the boyfriend were in panic. the boyfriend dressed up and came by the sitting room then he said "sir I am sorry for sleeping with your wife", Husband replied "It happens you can go". The boyfriend left. His wife never came out from the bedroom till it was time to sleep. The husband switched off the Television and went to sleep in the bedroom. He found his wife sitting on the floor crying. he did not talk to her in stead he went to sleep. In the morning when he wakes up, he saw his wife lying down dead. Police came and arrested him.

Who was wrong? If his wife took poison, is it his fault? was the law wrong by arresting him? Was justice served? Who was wrong?