The guy ordering was doing fine until the clerk started getting short with him about what he wanted on the sandwich. For some reason, not wanting mayo on the sandwich was a horrible offense or something. Anyway, the customer started getting nervous and he started to stutter, which rapidly turned into a vicious circle where the more he'd stutter, the more nervous he'd get which made him stutter even more, etc.
That's when the clerk blew it, in my opinion. He snapped his fingers in the guy's face a few times and said, "C'mon, kid! Spit it out! I haven't got all day!" Of course, this made it much worse and the young man could barely get a word out every ten seconds.
I so wanted to leap behind the counter and throttle the guy for being shockingly insensitive. As it was, I turned around and left to have lunch elsewhere. I'm going to be calling the place later to talk to the manager/owner because there was absolutely zero excuse to do that.