I've so far defied conventional wisdom by just saying flat out when I don't want to deal with off-hours 'fun' time. Which has pretty much been every time. During work hours? Sure no problem. No I'm not going to a team dinner or evening movie.
Most egregious one was a couple decades back when the team was arranging a nice holiday dinner. This was early in my career so I hadn't yet developed the comfort to reject, but the event was "pay your own way" and the restauraunt was a $120 a person, and that is not an inflation adjusted figure. I had barely enough to make rent at the time so there's no way I was going to piss away $120 just to eat with coworkers that I get to see every day anyway. I was so nervous declining, but it got a bit easier when they acted offended I wouldn't do it and said $120 wasn't really a lot of money.
So it's easy, which path did you like, giving anyone with access to a prop wheelchair however much they are trying to get out of you, or denying aid to anyone that ever managed to get up out of a wheelchair, however briefly?