This happened to my mom once at a church potluck.
Usually the potlucks are held after church, and if anyone has brought a special dish, they go in a few minutes early to get it ready.
My mom went in there to do whatever she needed to, and someone already in there, no joke said "Oh, pick up that spoon and stir those potatoes." Or whatever. I think they assumed she came in there to "help" and was looking for something to do, which she wasn't.
She just walked off.
But yea, I have like a hundred stories about church potlucks, lol.