If he was smoking meth, that would be enough to explain a lot of it for me. My only true experience of someone having a psychotic episode was with a friend of mine who I had no idea was even using. He was "normal", good job, clean cut, nice home, etc etc. We were neighbors a few streets apart and had met through mutual friends. We hung out, had BBQs, pubs, the usual stuff friends do.
He came over to my house once all paranoid and telling me that his neighbors had it in for him and that he had to move. He was telling me that he could hear them talking about him while he was in his bedroom and he feared they were going to come get him like vigilantes would get a bank robber in the old west.
I had to play emergency psychologist because he scared the crap out of me when he told me that he had a gun under his bed and would use it if he felt anyone would take it further than talking. I managed to calm him down and ask questions to try to use logic with him, but every time I went down the logical route to get to the root of his insanity, he only became a little more agitated and off topic.
Not knowing he was using, I obviously began to think that he was on something if not then, but maybe when he was at home. He really appeared relatively normal but seriously upset. So, finally, I just asked about using in a sort of indirect way and then he acknowledged he had a "couple of times". Based on what I hear, most people don't just use crystal meth a "couple of times." Then I said, "I'm not talking about you, but do you think it is possible that drugs can make someone think something that isn't real?" He agreed, but still I couldn't get him to acknowledge that maybe it was drugs that made him believe the neighbors were out to get him. I also noticed that everything he said the neighbors were saying were the things in his life he was ashamed of, that was very clear to me in our talk. I did find out he was surprisingly in therapy and I happened to know his medical doctor's name via playing detective, so as soon as he calmed down and I told him he could always call me if he felt threatened again, I managed to get ahold of his doctor and therapist. Then the big debate was whether or not to call the police. Neither therapist or doctor knew he was using and weren't really helpful to be quite honest. Both tried to shift the decision on me as to whether or not call the police. The doc said that if I felt anyone was in immediate harm, that I should call. I did not and he did not hurt anyone. However, in hindsight, I think I should have called the police. Anyway he then quickly sold his home and moved within two weeks.
Fast forward two years or so later. He came back to the area for a visit with friends and popped in for a visit. He told me that what he had experienced was some sort of brain virus that he developed as a result of some other medical issue he had that went undetected due to some medication he was taking. My inner voice said, yeah, that and your crystal meth. Talk about messy. Anyway, the point is that someone who can appear completely normal, clean cut, etc., can be complete time bomb. If LM was using meth, that might explain much of this.