Bet I can tell you something about the voting history of the guy who couldn't understand basic math or the concept of a sale, perseverated on that fact long enough to come back to the burger king that tried to give him a deal, called the cashier a racial slur and pulled out a gun.
Man with 10 kids opens mouth, grabs gun barrel with two hands, inserts barrel in mouth "Do it, let's go, bitch. My shift ends in 30 minutes I ain't got all day."
I'm thankful that in all my years of working in retail, I never had a gun pointed at me. Having said that, random people get so bent out of shape about the most ridiculous, inconsequential things and it can be close to impossible to predict who it's going to be or what is going to set them off.
Based on my experiences, if a customer is being indignant even after explaining that I was helping them out, I would apologize and remove the discount or ring the order up differently (if it was in my power to do so). More often than not, they calm down after they get what they want, even if it's to their own detriment. Granted, after calming down, a not insignificant number of these folks will realize their mistake and then they have to figure out a way to save face so they can ask for the discount to be reapplied.
