The thing is, Tank Commander is far more dangerous than Tank Man. Tank Man can simply be shot; most seem to believe that Tank Man was later executed, far out of sight of the international media. The regime survives if Tank Man dies, even if the death of Tank Man isn't the optimal outcome. The regime dies, however, if Tank Commander refuses to run over Tank Man. Eisenstein used the Odessa Steps to demonstrate the corruption of the Czarist regime, but the regime didn't die until the soldiers refused to shoot the demonstrators. The successor regime didn't die until Boris Yeltsin climbed on a tank in August 1991. While there's some mystery as to the fate of Tank Man, I don't doubt that the CCP found Tank Commander and put a bullet in the back of his head at the first opportunity.
From the always excellent Lawyers, Guns and Money