Ok, the guy's an idiot because he didn't pull back in time, and panicked when the tarpon tried to eat his arm. However, This place, Robbies, is one of the most popular tourist attractions in the upper Florida Keys. If you've been to the Islamorada area or driven by, you've stopped at Robbies, probably more than once. Anyplace you have masses of dumb-ass tourists, you have dumb-ass moves. (Boat ramps, lakes, and rivers included--we've all seen 'em or been 'em!)
This is another example of what happens when you "feed the bears." In this case, tarpon. They live there year-round and are hand-fed many times a day. Kinda like some "fish feeding stations" you see in these parts around dams, river overlooks, and even hatcheries. Although the tarpon are free to come and go, they aren't going anywhere when the food is free and the livin' is easy! They've become conditioned to eating from the hands of man.
When they are mishandled, employees advise visitors (who PAY for chum to feed these things, by the way) to be more careful. Overall, its not really harmful, although it gives the tarpon a bad name because true, "wild" tarpon DO NOT behave this easily, and are quite wary. But you can make any wary animal into a robotic loser by interfering with its natural environment. There are flats and channels within a mile of this place where the tarpon are spooky, moody, and a real challenge to fish for and catch.
I have fed these tarpon. Its kinda interesting. I've had one grab my hand right along with the food. More interesting. I was careful not to have my arm inhaled, as happened here. People have been pulled right off that dock though. Its just what it is, a tarpon feeding/petting zoo.
And yes, its illegal to remove one from the water in Florida unless you have an expensive "harvest" tag.
