Why do I have this very strong suspicion that Crystal is either black, hispanic or some other ethnicity who this fuck up assumes voted for Obama? Or maybe she's white, but wasn't wearing a cross or fish symbol necklace? Maybe she had piercings other than just the ears? With ankh earrings? Tattoos? Really, this fucker just needed an excuse to be a cheap bully.
As a manager, I would follow customers who stiff servers to aggressively but politely ask if the service was okay? Because, a "no grat" is considered reason to make a business decision about that server. And then they always say, "Oh the server was great, really I just didn't tip because of (w/e fucked up shit reason)". Then I tell them, "Okay, thanks. That helps me make my business decision to refuse service to you should you ever return here, and to award your server a 20% gratuity income replacement from our petty cash fund. Good day to you sir/madam!". And then I black list them on the lovely secret manager access-only comments section on OpenTable.com.......Fucker gets told by every restaurant he tries to book a table at that it is full-up, no res available LOL!