A colleague of mine was on that flight and seated in the rear of the aircraft. Before she was able to get up from her seat the water was already up to her knees. Behind her, it was already over the seat cushions! By the time the people in the back were able to exit, the water level in the rear of the aircraft was very high, and these folks didn't get to stand on a nice dry wing either. They had to chute into a raft that alrady had a good deal of water in it too. So... if you are in the very last row, inching forward with water steadily rising, and 3 or 4 people ahead of you decide to take even 30 seconds each (unrealistically conservative i know) to pull their luggage out of the overhead, your analysis that much ado is being made of nothing may undergo a drastic alteration and it is entirely plausible that you may, what with freezing water making its way up your body be compelled to riot.

I generally don't like obeying rules and consider myself a virtual cottage industry with regards to breaking every u.s. immigration, customs, and TSA regulation out there, but I hope I would not hold things up while deplaning in an emergency, and if I did, I would expect to be held accountable for endangering someone else's life.