See, I had the opposite happen to me. I went to WalMart and figured out a few minutes in that I needed a cart. Swung by the registers on the way out and look, a cart! Two items in it, blocking an aisle, no one in sight. I figure some idiot customer just left it sitting there, so I nudge the two items into one corner so I can remember to give them to a cashier later. Out of nowhere this harpy zooms down.
H: Hun, what are you doing? You need a cart? (Note: Loathe being called hun, especially when it's not a sincere term of endearment).
Me: ? Um...yes?
H: *yanks stuff out of my cart, copping MajorAttitude + Tone squared, the sort you get from teenagers* Well, that's just fine. I was using that for returns, but
Me: I-I'm sorry--
H: Oh, no, I wasn't using it. I'll just get ANOTHER ONE. *slams items down on a counter, stalks off*
I'm sure this problem could have been solved had I been calm and able to say "I'm sorry, I thought someone left it here and I wanted it out of your hair." However, I'd learned that my uncle had serious cancer just two or three hours earlier AND another aunt had actually died, so that condescending attitude was the last straw. I ended up just taking the cart, running off into the fabric section, and crying for the next half hour.