2 things stick out to me, IT is a major mis match against the cavs. He is a bad defensive liability and with Clevelands height they can keep him in check. Now whether that was due to injury or a bad match up its tough to say. Maybe a bit of both. Regardless the Celtics sucked in game and 1 and 2 no matter how you slice it.
My last thought is.. Did Lebron even try tonight? When he did decide to go to the rim he didn't have that same explosiveness. Its almost like somebody in the NBA said to Lebron "try not to beat down the Celtics tonight, let it go 5 or 6 games so we can drum up more excitement and make some more money"
lol I am joking but honestly if you watched him he was not the same player tonight. Passing it off even at the end of the game, he didn't try to take over.