Anvil's response may be "ouch," but it's spot on. You are concerning yourself way too much with him.
My thoughts:
Sounds to me like he was just casting his line to see if he would get a bite. And he did. Just that little bit of contact has you all in a dither about whether or not he misses you, how he is doing, does he have remorse, etc.
This is all my personal opinion from reading your posts, but...if you leave the door open, even a crack, he will worm his way in. He proved it with that one text. You don't need to know more of what he is in order to move on. You already know...he's an addict, a user, a thief, and an azzhole. What more do you need to know?