The way it works is there is an official looking at the clock and if it hits zero then he looks at the ball and if they snap it at that time then they don't call it a delay of game. It's not immediately a flag.
Again let me ask you. Do you think we would have gotten away with those same calls? The answer is no. The NFL is a complete joke. We're gonna have to win by about 3 TDs every game to keep the refs out of it