We're all experts after the event. Not wanting to diss ya.
On plenty of occasions I've seen a big Ace, and lumped in my chips in the heat of the moment. It's easy to do.
In fact, that's maybe one of the principle reasons I wasn't playing in the main event myself this year.

It's hard to find someone who will fold any cards for 3-1 pre-flop. I tend to find they might fold on the flop between 20-30% of the time though. It's a strong move in that spot for blind defence, and maximizing your chances of tournament survival.
I find some weak players who even lay down a small pocket pair on the flop (when you bet your remaining chips, just a third of the pot.)