Well, from what I've heard, the stingray attacked him because he tried to handle it and it panicked.
And you know, he put himself in the line of fire. That's what he did, that's what he loved doing, and that's what made him unique. I'm one hundred percent certain that every time he did these things, he was fully prepared to be injured or even die. It happens.
Saying he brought it upon himself is no insult to the man. Because putting himself in life-threatening situations was his passion. Remember his Fed-Ex commercial from a few years back where he was bit by an incredibly deadly snake, but because the anti-venom wasn't shipped via Fed-Ex, it didn't get there in time and he died?
He was fully aware of the risk he took every time he stepped out there, and dare I say he relished in it. It wasn't a freak accident because he knew what he was doing was dangerous. It would have been a freak accident if he was eating a sandwich in his tent when a buffalo stampede came by and trampled him to death.