Yes, my experience and observations are that reactions to emergency situations are largely reflex or instinct. If you've had an opportunity to experience that particular kind of emergency before you have a better chance of keeping your wits, but in a surprising novel situation you don't really have time to think it out. You either act or you don't, and given time to examine the situation you will always wish you had done something at least a little differently.

It's important to keep this in mind when watching a video after an event. Chances are that as a viewer you know SOMETHING is going to happen before you even start the video, which puts you well ahead of the participants already, and of course by the time you've seen the slow-mo you can plot a better course of action than was taken at the time.