I think Lance was just playing it cool and covering Beloki, with 2 more weeks of the tour left it would make sense to conserve yourself. Anybody notice his face didn't seem as pain striken as the other attackers? How about his riding style, when he was seated he wasn't rocking very much either. And then right at the end he pretty much left those other guys in that sprint to the finish. Of course I could be wrong as well, but he sure didn't look whipped to me.
And that tactic right at the base of the climb, very smart move. To bad it didn't drop everybody (or well GC contenders), but they really poured it on.
Andrew