Same response as to GR to you, but also....

"This woman, I'm guessing 27 or 28 years-old, came up to me at work today to buy some cookies. One of my co-workers came up to her and said something. Her immediate response was, 'yeah, save it for someone who cares, buster!'"

Unless she looked Mexican (or some other South American) and it was an innocent mistake then the dude had no business talking to her in a language she shouldn't be assumed to know.
If she looked South American (can I just say Mestizo?) then she was in the wrong for being so rude, but only if she said it in a serious, obviously non-jocular manner.

If neither looked Mestizo in any way then it could be assumed that he was trying to use foreign language to pick up on the girl (like how French used to be a stereotypcally romantic language [is it still??????]), then the jilt may have been harsh, but not racist in any way.

I'm sorry, LGs, but you're just taking this whole thing way too personally and way too seriously.
I know Mexicans, they don't give a flying fuck if you don't like their language or if they are jilted.
They care if you bad mouth their family members (especially their dads) and they care if you talk smack about religion (even the gang-banger who could care less about the practical aspect of Chirstianity), but I'd be surprised if any of 'em would get as uptight about someone not liking their language as you and GR are.

You guys obviously don't know Mexicans at all.
Just like every other political corrector who will defend the "pathetic, can't defend themselves blackies, and mexies" whom most of them have never even met, other than their gardener who lets them get away with paying them $3/hour.

Honestly...