I think Lebron is exhausted. Remember, this is the 3rd straight finals trip. Plus the Olympics. And this season, basically, has been mostly him as Wade nursed an injury. These, plus the Bulls and Pacers in the 2nd round and ECF.
Lets see if he can find another gear.
Thus far, this series has surprised me. I thought all along that Miami would win since they can match or top Spurs defense and are the superior team offensively. But their offense has faltered and the defense is not so good.