This question isn't about whether the code of SO actually prevents you from voting after posting an answer, I know that's possible. I've answered many questions correctly only to find a different-but-equally-valid answer posted five minutes later. I upvote such answers, no problem there.
I'm wondering about what happens in the above situation if the "five minutes later answers" are wrong or not-exactly-incorrect-but-problematic-for-some-reason. If I saw that happen, I would want to downvote the other answers, but I would be afraid of setting off whatever mechanism SO uses to detect tactical downvotes (AKA "angering the ATWOOD").
The best solution I can think of is leaving comments indicating what's wrong with the other answers and hoping other people perform the downvotes, but that seems... suboptimal. And it barely works at all if the other answers are already heavily upvoted. Does anyone have a better idea?