I work and live in the Everglades, working with and around alligators all day long.
First off, in the beginning, the cat is right in front of the alligator. Alligators cannot see directly in front of them or behind them so that wasn't all that impressive.
Second, this is a stupid "trick" and is putting that cat in serious harm's way.
I would also like to know what time of year this was taken, how cold was it that day, had they already eaten, etc.
The fact that the second alligator came up out of the water after the cat is natural. That is exactly how an alligator would react towards a cat or any other small mammal. Why it backed up makes me seriously question what has gone on with these alligators at the hands of humans.
Unlike the people in the video, I don't find this to be a laughing matter.