Say you’re a tenpercentery with a hot agent who’s also a hot head. And say he walks off the job in a huff from time to time. Well, if you’re the Gersh Agency, you let John Buzzetti blow off steam and then welcome him back again and again. It’s because the New York-based partner and theatrical lit agent reps a bunch of quality musical theater and playwrighting talent. (Gersh’s theater department expanded in 2006 when it annexed the Joyce Ketay Agency.) So I’m told that last week he blew up because he thought one of his colleagues was giving him attitude and then walked off the the job. Not even Bob and David Gersh knew when or if he was returning to work. But Buzzetti was back in the office today. And this isn’t the first time he’s gone AWOL. Gersh agents recall that a month ago Buzzetti pitched a fit and walked out when the air conditioning system wasn’t working. “He throws up his hands and says, ‘I’m done,’ over a ridiculous thing,” one insider tells me about Buzzetti. “He’s a hot head. But we’re not worried because he’s got many years left on his contract.” Question is: how long will Gersh stay cool with such behavior?