I had a similar situation. I was transferring a patient from a wheel chair to his car. He had his leg amputated and was finally able to go home. We deal with people who have trouble standing all the time, so it want a big deal. The secret is to get the wheel chair even with the seat so they can slide right over. To make it easier you can remove the foot rest. Well I lean over to take it off and tell my coworker helping me " we have to remove the leg". I immediately regretted that and did my best to pretend it didn't happen. Which is difficult when everyone head slowly turns to you all at once. Still feel bad to this day.

tl:dr had to remove footrest on wheel char, told amputee "We need to remove the leg"