I Don't Work Here

Yesterday (or maybe it was Monday) I had the following conversation at the always-classy Dollar Tree store:

ME: *noticing a woman stocking the shelves, and assuming she was an employee* "Excuse me, do you know where..."

WOMAN: "Oh I don't work here, I work at McDonald's."

ME: "Uhhh, sorry..."

Q: Who tells you not only that they "Don't work here" (perfectly normal response), but also informs you of where they do work, especially when that place is McDonald's?

A: Someone who works at McDonald's.

*no insult is intended or implied towards those who work at McDonald's or any other fast food place.