I thought the exact same thing, and was ranting about the fact the Whale in question should have been made into sushi long ago. Then one of my co-workers said that the people who sold the whale to the park disclosed that it had killed before and it should not be used in shows or be around any trainers...something to that effect. Have not had time to search the interwebs to determine the validity yet, though. If that is the case I would bet the victim's family has the inside track to being the next owner of Sea-World.
This thread is really old, but from what I understood is that no trainers got in the water with it because of its history. But it grabbed the trainer from a side platform.
I'm sure that the trainer signed some sort of contract saying working with ginormous animals called killer whales was dangerous, and she could get killed. And I'm sure she was aware of that one's particular history. So, I wonder if the family will sue.