The fuzz says that a man crossing Hayes and Stanyan streets in Golden Gate Park (against a red light) was punched after getting into an altercation with motorist yesterday afternoon. It went something like this: The guy in the car honked, the pedestrian responded by slamming his backpack on the hood of the vehicle, then the equally mentally-deficient driver got out of the car and clocked the pedestrian, and said pedestrian fell to the ground and conked his head. The 53-year-old man remains in the hospital in serious condition with a nasty head injury. The suspect is still at large.