I truly believe that he is at the point in his career that he is finally willing to be a role player off the bench and willing to sacrifice for the good of the team. I'm sure he realizes the bad taste he left in the collective NBA mouth when he left.
However, I don't believe his skill is worth giving a roster spot to at this point. His style of play, even if he commits to passing the ball, just isn't conducive to championship basketball, whether as a role player or as a starter. He's never been a particularly good defender and for a guy who relies on quickness, as a 38 year old, has got to be slower now. Combine that with the number of injuries he's had over the last five years or so, the skill no longer outweighs the risk his ego would bring.