At the bottom of which is this interesting paragraph:

And for a slightly different perspective, here are some comments from Christine Negroni, aviation safety journalist and author of the Flying Lessons blog:

Like you, I found myself shaking my head when I saw the videos or read reports of people taking their carry on luggage off the plane. Then I interviewed a passenger on Asiana 214 [the 2013 crash-landing of a 777 in San Francisco] who had done so and was surprised by his explanation. He told me that when the plane came to a stop and the evacuation began, he acted by habit in gathering his things and only afterward did he realize what he was doing. So I think we cannot discount the effect of altered state of consciousness as playing a role in this behavior. You may have read about this as a form of “negative panic.”

Which may lead to a revision of Hanlon’s razor:

”Never attribute to stupidity that which can be adequately explained by indifference.”

Even with flight attendants desperately screaming “leave your bags!” and a fire raging? More likely that person was just trying to hide his embarrassment.

I've never been in a flight accident (thankfully), but from my experience in amateur kickboxing fights when you're in a stressful environment (in a ring) and everyone is screaming, I don't think I ever heard a thing my corner was yelling at me, even if they were only a few metres away, my brain just went into auto-pilot. So I wouldn't discount his story.

I was in a low-speed motorcycle accident once (no real injuries, just a long bruise down one side) and remember literally nothing that happened in the first five minutes afterwards, even though I'd somehow gotten my bike off the road with the help of a witness during that time. I didn't even consciously check myself for injuries until after I'd copied down the license plate number said witness shared with me.