"highly unlikely that the shark got into the pond by itself because there are grates on the drainage outflows to prevent alligators from getting in."
Well no shit Sherlock.
I haven't read anything recently about tornados sucking up sharks and flinging them around and I don't think a shark this size could have been dropped by a seabird, so I'm pretty sure somebody who knows that bull sharks can live in fresh water put it there.
They probably thought it would be hilarious. I think it's hilarious.
City workers in Indian River don't. The shark probably doesn't think so either.