While the surgeon was pointing to the left side of OP, they just answered “it’s the right side” meaning that the right side was the right side … Guess what the surgeon did.
“It’s my right, your left” (not common but has occurred multiple times).
The more frequent one is where someone is trying to say “medial side of left leg” and say “it’s the right side of of my left leg”.
It seems dumb but if it saves me from having someone dissect my right knee when I wanted someone to bolt a new AC ligament into my left one, I'm all for it.