Contador
I don’t think that Lance was even talking about the fact that Contador bonked. I think that what he was referring to was the tactical decision to go with Colom (at the time, 2:35 down on GC) on the Col de Bourigaille instead of sitting on Luis León Sánchez (at the time, only 1:13 back on GC and a much bigger threat) and biding his time. It was a good bet that Caisse d'Epargne would not be prepared to jeopardize its podium position and would have pursued Colom at some point anyway. When you are isolated, sometimes you have to use your opponents own goals against them.
It is still entirely possible that, upon waiting, Colom would have soloed away for the win, or that Contador would have bonked on the final climb, but it is also more likely that he would have lost less time and may have saved his GC chances.
It sure is a lot harder to sit and do nothing when a GC contender leaps away than it is to jump on the wheel, but it is the voice of experience that tells you that. It is often said that to win, you need to be prepared to lose. Perhaps that was the lesson Lance was talking about.