I agree, the lady should not have been using the stall.

I'm not disabled (yet, tho I expect to be one day), I do get some bad back pain occasionally. (had a car accident in 99, I think the chiropractor I saw after that did more damage to my back than the accident did) The pain isnt something that happens all the time, but when it hits, I can barely move. So, I have used the handicap stall on a few occasions because the toilets in the handicap stall are usually taller and I dont have to painfully scrunch myself up to sit down on one of them. (why dont they just put the taller toilets in all the stalls? I swear, some places have toilets that would be too low for even a small child)

Plus, the rails are helpful when my back has been really bad.

Thankfully I havent had the horrible back pain in several months (been walking as a therapy for it) and I havent had to use a handicap stall for quite awhile because of that.