Well, let me add that both passengers appeared quite vigorous to me. He was mobile on his own, he just used a cane. In my experience canes are generally used to relieve joint pain whether by arthritis or other disease. It does not mean the passenger is incapacitated. I wear eyeglasses. Should I be excluded from an exit row because of that? They could get knocked off in an emergency, but I can still see pretty well -- not perfect, but good enough to assist, in my opinion. In an emergency, I expect the older gentlemen would have come through fine. The crew member was closer to the situation than I, I did not hear the whole conversation, and I think she probably made a good call.
Frankly, what I worry about most concerning evacuations are the number of passengers I notice on takeoff and landing that have their shoes off or untied. One of the most common-sense preparations for a possible accident would be to keep your shoes on, in my view. What are the shoeless going to do with broken plastic, hot metal shards, and possibly live electrical wiring on the floor or ground? Their shoes will be long gone, 10 rows forward.