Why didn't the TSA agents stop her? She was still obviously in sight of them, and that certainly seems to be an exhibit of suspicious behavior. After going through in a wheelchair and then jumping up to rush off with two heavy bags, I'm surprised she wasn't tackled and brought to a pivate interview room for several hours of intense screening.
Of course, since we're hearing about this more than third hand, it could just as easily be a case where the person could walk but not stand for long stretches, so when she was done with security she got up, retrieved her purse and carry-on and walked to her gate.
They're not allowed to ask - it's like people with service dogs. Here's the NYT article about it. Airline employees say they see a marked uptick in the number of wheelchair requests when the security lines are long, and the wheelchairs brought to meet passengers at the end of the flights end up unused because the passengers sit in wheelchairs to be first on the plane but don't want to wait to be the last off so they just walk off instead. They also say it's only a small percentage of people who abuse the system like this, though.
My Mom needed the wheel chairs at airports after she broke her hip. She normally used a cane but the standing still in lines and people nearly shoving* her over in lines at airports meant she needed a wheel chair. She shocked the people helping her, by asking if she could be last on. She only had her purse and cane as carry ons - and she was claustrophobic.
*I have to give the security at Toronto Airport kudos. We were in US customs. The line snaked between a pillar and the wall. Our luggage cart was too wide. Dad and I went around the outside of the pillar and joined MOm and Sis in line when they moved up to that point.
This woman behind US started yelling we were cutting, and nearly sent Mom flying by slamming her rollie bag into Mom. She tried a 2nd time and Sis took the rollie cart away from her. Security came over the people in front of us and the people behind rollie bag woman all confirmed it was obvious we were together and like everyone else with the airport cart had had to go round the other side of the pillar, and that the woman had delibrately hit Mom and was trying to hit her again. Mom already had a nasty bruise forming on the back of her leg.
They asked the woman to come with them. She smuggly started walking to the front of the line. THey stopped her and escorted her to the end of another line, and told her that if she touched another person they would arrest her for assault.
The kicker - her plane was canceled because of a hurricane/TD on the East coast of the US. She saw us after it was announced and yelled we made her late so they canceled the flight.
Dad thought her real problem was that US customs and Immigration had 2 lanes reserved for planes close to taking off. They went through the other lines checking tickets and moved certain planes to the "express" lane. They kept refusing to move her, and taking planes with later departure times, because they were knew the fight would be canceled and were waiting for official word.
Which begs a question. In a situation like this were you go through customs before boarding the flight into the US - what happens when the flight is canceled. Do you have to leave through Canadian Customs?