Dunno about the shift. To me it sounds like he was a little closer to experiencing his own difficult feelings in that episode than his prior behavior. I'd say that shifts in that direction are required to heal and improve.
Honestly, I'd not worry too much about it, unless it becomes part of a larger trend, either to be more violent (worrying) or more in touch with his feelings (hopeful).
I'd focus instead on what YOU did.
His behavior was completely unmanageable. You called police who got him under the care of people who can do more for him than you can.

That was excellent work on your part! Pat yourself on the back a couple times!
He may later blame you instead of thanking you for your actions here. In this case, it is YOUR judgement and YOUR moral compass you were following, not his, and you did it right. Don't let him convince you otherwise!