spot on.
There are many other plausible explanations.
A personal experience that's somewhat similar.
I'm somewhat similar to the guy you're talking about. I really did have a traumatic childhood. (not just a assumption) I can function just fine for the most part. But i do have trouble letting people in. So i pull them in. And push them away. Pull, push, pull, push. I had a similar situation with a girl that lasted for 4 years. Believe me that it didn't make her happy. And i only felt guilty for hurting her feelings and wasting 4 years of her life. I loved that girl. But i wasn't ready yet to let somebody inside my walls. And every time she was trying to get in i would push her away. So even if you're right and he has some problem caused by some trauma. You are not helping him or yourself if you hold on.
You can make it clear you're available. You can ask him what's going on and what he wants. But pushing and pulling over and over isn't going to make anyone happy. At one point you have to let go. And that isn't selfish. It's wise.