Your son's friend is exactly where he wants to be. You said yourself you son told him he only had to think of a place to be and he would be there which the young man acknowledged.
Sometimes we just want to be alone to think. 3 years? Time does not matter on the other side. I was in a similar place for much, much longer in between lives once.
If you hit rock bottom, start picking up rocks.
By embracing my imperfections I am becoming perfect.