He's a politician; he plays the game. It wasn't his call to contest the Florida vote. Sorry, I just believe him that he wouldn't want the military ballots thrown out.
If Lieberman had even a shred of decency, he would have walked away from Gore when the 2000 debacle began. There is no way an "honest Joe" could go along with such a blatently illegal attempt.
There is no moral equivalency - Bush was morally and ethically required to resist the illegal actions of Gore and Daley. Lieberman was morally and ethically required to break from Gore/Daley and say that they were doing wrong. To "play along to the hilt," is not only being an accessory to the crime but an absolute collapse of character.
Playing the game is the excuse of the scum politician and Lieberman blew whichever way the media wind blew, a flaw of the scum politician.
It's an interesting debate. I do think Dick Nixon deserves admiration for not contesting 1960, though there are always those who say he just wanted to preserve his hide for a future run.
From Day One, I blasted Gore for not following Nixon's precedent of putting the country ahead of his own victory. But it wouldn't have been illegal for Nixon to contest, and it wasn't illegal for Gore to contest. Just unseemly of a statesman. Things got out of hand with the contest, and some very wrong things were attempted by the Gore side. But I think you exaggerate the degree to which there was a moral mandate for Joe Lieberman to reject the entire 2000 debacle.