No polite Southerner would have made that remark. The guy who said that about your friend was (1) rude, and (2) a show-off.
Polite Southerners will do anything not to offend someone.
I've often said, a polite southern woman will never say to your face - what she can say behind your back. :~)
My favorite description is that a Southerner will never insult you accidentally. We're acutely aware of manners, so if a Yankee insult is a bludgeon, a Southern insult is a stiletto. By the time you figure out you've been insulted, we're already on the way home.
As an example, my grandmother recently told me a story about her grandmother, one of the Athens Howards, who was quite acid-tongued by Southern standards.
She had a party, or afternoon tea or some such. One local young lady, who was quite homely and not too bright but fancied herself a beauty, coquettishly piped up, "Who'll walk me home? It's geting so a pretty girl isn't safe walking home alone these days." I can only imagine that she was batting her lashes and flipping her hair as she said it. Home was about a couple hundred yards down the road. There were no immediate takers.
My great-great grandmother said, "You don't need to worry about that, dear. The Lord has placed his protective arm around you, and I'm sure you're in no danger." I don't think the young lady ever figured out she'd been, in the modern vernacular, dissed in front of everyone.