If I were him, I'd definitely stayed with the Heat. They are paper-thin at the 5 and he could have got way more money from the Heat also. (If I'm right about the Heat owning his Bird rights.) I'm sure Jermaine knew that Miami has loads of cap space, so he could figure that the team will get a huge boost and will probably be a championship contender. (Even if noone was sure about LeBron.) Did he join the Celtics, because he was humiliated by Perk in the playoffs? (If you can't beat 'em, join 'em.) Or did he want to join a contender and he wasn't sure Miami would be one? Chemistry-issues, maybe? Lastly, could he have got more than the MLE from a non-contender? To be honest, I kind of doubt that...