LeBron had a pretty good point in a way. He's the Heats most valuable defender, and the defense was what, 5th? 7th? And they did it without a defensively dominant big man to keep guys away from the cup. He is likely the league's most versatile defender.
But DPOY is a bridge too far for me. Noah, Duncan, and I guess Gasol since he won, all rate above him, and for the second half of the season I'd even put Dwight Howard and Larry Sanders in there. Just too much value in a big time rim defender to justify LeBron eclipsing them.