The day one needs a limb removed from their body is presumably a very bad day. Not much else could make it worse. Sure, surgery complications, infection or anesthesia are all concerns. However, it is not as if that is much worse than having your leg or arm chopped off. Oh, but it can get worse. What if you wake up and the wrong leg is gone or both of them are gone instead of one?
Nearly three and a half of every leg amputation will involve the wrong leg. Yep, you heard that right. At least three out of every million people who have had a leg removed have had to have both legs removed due to surgical error. You could wake up in the recovery room, only to realize that you have to go through yet another amputation or that you got one more than you expected.
There is a lot of discussion on how this is a really low number. Sure, it is a really low number if we are talking about something silly like three in one million amputees get hives after surgery. We're talking about whole healthy limbs being chopped off by negligent doctors! Yeah, three in a million is three in a million too many.