God i still get confused between CODPIE and CHIPPED!
On a short turnaround, early morning first flight of the day you might find the crew are going to make a snap judgement at who they either let sit there or direct to the seat (depending on the airline's seating policy).
If a pax comes up to me with a limp but is otherwise "Able Bodied" I might very well allow that person to sit there, but if the pax wasn't able to open the door, egress from the exit and help with the evacuation from that door then of course they would be moved from that seat.
Cabin Crew will have, after all, opened that overwing/exit door and know how heavy and sometimes bloody difficult they are to move about, esp when your in the seated position....unless you're lucky to be on a Boeing 737NG
I have and continue to move "Able Bodied" pax from that row if they do not fit that criteria, esp when the dad whispers in the tiny kids ear "say your 16 son!"