Frustrated with being blamed

Part vent, with some questions at the end. Sorry if this is stupid or not the right place... My person called me from Remand today after he went dark a month ago. Hes been there for 2.5 months. Our last conversation was a difficult one where he didn't like something i had to say and it got heated, words were exchanged, and he hung up on me. I sent him one letter explaining what I had said (because I knew he took it wrong), with the intention of not continuing to send letters if I did not get a response.

I knew he was going to bring it up when I answered his call today. I felt level headed, but I am not good at explaining myself on the best of days even though i do my best, much less over a call with shit reception. Turns out he never got my letter. And turns out he thought I said something that I didn't. This was not conducive to a good call, but I didn't lose it like last time.

But what caught me off guard today was that he keeps pointing to me as at least part of the reason he's there. And I'm having a really hard time trying to figure out how to approach that in a non-confrontational way. Yes, I called the cops one year ago after he got out of control tweaking and getting aggressive in my apartment at 1am, but the request was just for them to remove him. He ended up assaulting them. Since then hes caught about 10 other charges, ranging from failing to appear to assault with a weapon and drug charges. I was never involved in contacting police or even present for the rest. But he feels like im responsible because I ended up kicking him out. Yet, several charges are from when he was allowed to be at my place, but relapsed and subsequently not allowed back while high, and ended up doing some tweaker shit out in the wild. He can't see that his addiction is the root of his legal problems. Before he started using he wouldn't have dreamed of doing the stuff he's done.

What is a non-confrontational way of explaining this, on a timed call? Is it even worth it? I am staying in contact with him because I believe that he can change if he wants to, but mostly because I have all of his belongings (his family or other friends wont take them), and have been taking care of his dog until he can take care of him himself. Also, why wouldn't he have received my letter?