I have to look it up, but I read on MLB Trade rumors that many pitchers were saying privately that any PED user was a target. I'm not sure that there were any specific threats against ARod. However, I think every baseball fan was expecting ARod to be thrown at, and even on this board, that option was heavily discussed.
Still, I can't blame O'Nora, it's a tough judgement call either way, and he's damned if he does and damned if he doesn't.