You don't win a GT stage at random, I'm sorry but you are way wide of the mark with that assertion.
Millar was strong enough to win and was the smartest guy in the break. I accept you may not see that as impressive (I doubt you even watched the stage - are you sure there were no attacks in that break? Funny that it came to a sprint-á-deux from a group of five, considering there were no attacks, yeah? Are you sure Millar didn't mark the moves that mattered?) but to mark it down as a random occurrence is doing stage hunters like Voeckler or Chavanel a disservice.
Actually, considering how "random" a breakaway win apparently is, isn't it odd how often Voeckler, Fedrigo, Moncoutie, Luis Leon Sanchez, Lastras win GT stages, from a break? Amazing how lucky Virenque and Jaja got through their careers too. Oh and isn't it odd that Hushovd was lucky enough to win two Tour stages last year, you know, with it being such a random occurrence?