I'd have to tlk to the graveyarders, but a few things don't add up. First off, Prospect (as mentioned the W/C contractor) has to scan into the gate. Now, granted this was an RJ, and assuming it was not a jetway board, they weren't at the podium, I'm pretty sure they still need to scan in, and the Channel 8 link cites the woman being picked up. Second, assuming most of the graveyarders are the same since I left graves not too long ago, they would probably say "it's not my job", but they would also tell the supervisor. Fourth, we don't deplane disabled passengers without Prospect being there. The aisle chairs are too uncomfortable. Fifth, TWELVE HOURS?!?!?!?!? You can NOT not be seen at McCarran for 12 hours. It's impossible (unless you TRY to hide).
Here's what I think happened. The woman was deplaned. She was brought upstairs (a long way to the elevator from some gates). Prospect then asked her where to go and she probably made some comment about missing her flight nd having a lot of time to kill so asked or agreed to the slots or a quiet spot for the night.