Michael Bloomberg has never been especially cozy with the City Hall press corps, and with temperatures recently soaring, the Mayor has gotten shorter with reporters. During an outdoor news conference yesterday Bloomberg was caught off-guard by a question about the brawl that broke out at the freshly reopened McCarren Park Pool in Williamsburg late last week. ““I had no idea there was an incident,” he said. “What was the incident? Did someone go swimming?” The reporter explained the fight to him–a group of teenagers had dragged a lifeguard into the pool and punched him about the head.