The people he deals with don't have any rule book they follow. Likewise, it's up to him who he wants to go after. Clearly, he decided that turn around is fair g

The people he deals with don't have any rule book they follow. Likewise, it's up to him who he wants to go after. Clearly, he decided that turn around is fair game and went after his wife. Unfortunately when you deal with criminals, you can't really justify any behavior on either side since they are both operating outside the bounds of the legal system. Outcomes are mooted in the context of the world they are operating in when it's devoid of rules, honor and morality among the participants.