In the situation that has been described, after they entered their attention was on the perp and not on where the cameraman was positioned. It sounds like the cameraman whom I believe was hit in the head was possibly ducking when the round hit him. If that is true it is possible that he would have been hit in his ballistic vest if he was not taking cover. The cops had no way to control where he was at and he obviously thought at first he was not in a vulnerable position. Watch the show a few times and it becomes obvious that the cops concentrate on the criminal and the cameraman has a lot of freedom of movement about the scene.
The news account I read on another site said the sound man got separated from the cameraman. If one is running sound, one should always be where the camera is. Anyway, he was shot in the armpit area and the bullet traveled to his chest. A very unfortunate shot, even though he was wearing a vest.