Neither of them could actually defend O'Neal one-on-one, but they could limit his shot attempts and wear him down solo, and that was enough. For the Pistons, it required both Wallaces to handle him.
As O'Neal's impact decreased, Wade had a difficult time against the Mavericks' explosive perimeter players. In the first game, he made 11 out of 25 shots, and in the second game, his shooting plummeted to 6 out of 19 attempts.
On June 14th, during the third game of the Finals, just as Zhang Yang anticipated, the "body-hair whistle" came again... Wade went to the free-throw line 18 times, the Miami Heat outscored the Mavericks 31 to 19 in the final quarter, reversing the score to 98-96 and bringing the series to 2-1.
Zhang Yang didn't watch the next three games; keeping an eye on the scores was enough.
Actually, the refereeing wasn't 'problematic'; every time Wade stepped to the free-throw line, his opponents did indeed commit substantial fouls on him.