Calm as can be. The guy just kept ramping up his order the more he watched.
Language warning.
And to prove I will forever be a skeptic: One of these days companies like Taco Bell will set this whole thing up. Just pay a couple of chicks to beat the crap out of each other while you pay another guy to film it while he places an order for a delicious quesadilla. And then hope it goes viral. (Don't believe me? There's some evidence that the "kid smashes windshield of $250,000 car" is a set up.)
P.S. Did they not ask him if he wanted sauce? What kind of joint are they running there?