And maybe that's the key...he's not rational.
Omit "maybe" from this sentence, and you've answered your own question.
Keep the focus on you. What he does or doesn't do is no longer your concern, and trying to figure out why he does what he does is a recipe for a cognitive feedback loop that'll trap you. And I think you've had enough of being trapped.
That said...the fact his "whatever" is in The Clink (my affectionate term for a psych ward) does not surprise me.