I try not to think about the dumb mistakes they've made to lose games, but that one really hurt. Although, I will say Shanahan's decision to put the game on Cundiff's foot from 62-yards out (or 47-yards, to be honest) was a real head-scratcher as well. I'd MUCH rather have seen Griffin with the game in his hands in that situation, but maybe Shanahan was trying not to give the rookie too much too early? I don't know.
I DO know that watching Grossman with the game on the line last year, I just KNEW he was going to do something stupid to mess it up and lose the game. I had zero confidence. With Griffin, its pretty much the exact opposite of that, which is why I was furious that Shanahan settled for a 62-yard field goal that everyone (including probably Cundiff) knew had about a 10% chance of going in.
EDIT: The more I think about it, the more I think the 15-yard penalty was a blessing in disguise, a chance for Griffin to win the game on his own, that Shanahan passed up. Because chances are, Cundiff misses from 47 also, but that's a much more "makeable" field goal than 62-yards.