I said that as well yesterday. Instead of killing the 'killer' whale, put it back to it's proper environment. If it can't adapt, that's not the whale's fault for having it in captivity for so long.
For many thousands of years, predators that were a threat to humans were killed. The ones who survived did so by figuring out that attacking humans was a fast way to die.
Think of it as evolution in action.
For the past few decades we've abandoned this operating basis. I think it's a mistake.
That killer whale is acclimated to man and could approach any swimmer it encountered.