Plot hole: When Chris finds the informant's phone and calls Abel, it makes no sense for Abel to answer the call: Abel wouldn't answer the number of the phone he is trying to find and get rid of in order for people not to find out he called him and ordered Chris's house vandalization. Also, he knows the phone is somewhere around the house and looks for it there, and having seen Chris get it, he can easily deduce Chris found it - which only makes his decision of answering nonchalantly all the more peculiar.
Plot hole: At the end, when Chris finds the informant's phone, he sees that there are 2 voicemail messages. Instead of listening to them, he calls the last number, which reveals Abel is responsible for the break-in when he answers and in turn reveals to Abel that Chris knows about the break-in. It would make more sense to just listen to the voicemails, as Chris became immediately suspicious when he saw them. Considering Chris called the last number, he must have known that the last number was also the person who left the voicemails. Very deliberately done to bring realizations between Chris and Abel for a climax.
Answer: He already had a much bigger mental problem in general, and not just about his wife or with Chris and Lisa. They were merely one of many triggers that could set him off.
raywest ★