By Yelena Mandenberg & Yelena Mandenberg A man was shot in the head on a packed New York City subway as terrified passengers dropped to the floor and took covern. A heart-stopping video captured the dramatic moment a group of New Yorkers instinctively ducked down as a gunshot went off at the Hoyt-Schermerhorn, critically injuring a 36-year-old man. The clip, posted on X by ABC journalist Joyce Philippe, who happened to be in the car when the shot fired, shows the crowd ducking down and shouting. One very audible commuter yelled, “where’s the NYPD?” as she crouched behind seats. Some people hel…