The rat is obviously mistaken, he was safe. There's no reason to see a replay, or explain anything. He's safe because the ump ruled that he was safe.
For example- Bang-bang play at first, I call and signal out. Player throws his hands in the air in disgust, walks to the dugout and passes manager on his way.
Manager says, "C'mon blue, he was safe!"
I respond, "Skip, if he was safe he'd still be standing on first. Look, he's getting a drink in the dugout... he's obviously out."
At this point the manager looks at me with suprise and walks back to the dugout.