Yes, you are right, the directors and network personnel are in charge of replay. But what would I want the announcers to say?
Okay, something like "the replay showed that the ball hit the bat, but Jeff Nelson only got one look at it, and that was in real time, without the benefit of all the slow motion replays that we have the luxury of viewing, so let's not all blame everything on the umpire."
Or words to that effect.