Emphasis: This is not a why downvote, or when is it ok to downvote, or what to do when voted down. This question is about a particular pattern of downvoting.
Recently, one of my answers was downvoted. It wasn't the best answer, but certainly not technically incorrect. It got me to looking at another user's voting pattern because I saw something odd.
Every answer that wasn't this particular user's had been downvoted (modulo one that was a one-liner summary of his answer).
So, there are two aspects to the pattern:
downvoting other answers is like upvoting yours; your answer instantly has a score that is one higher than it otherwise would, relative everyone else's (at the time of answering)
early on in the answering process, this can have a definite impact on the reputation you receive for an answer because your answer (very possibly later) now bubbles to the top because it has 0 points, versus the other answers which have -1
Regarding point #2, you can further "game" the system by undoing your downvote after you've gotten a couple of votes up, undoing any (minimal) damage to your rep and the others'.
Is this a pattern people have noticed much? Is it worth trying to discourage it? Or am I just a sore downvote recipient?
I'm not trying to get back at this guy. His answer to the question that started all this is very detailed and informative, mine leads you down a different (not as useful) path.
I checked a few other questions he'd answered and noticed a similar pattern on questions he'd answered — many technically sound answers had -1 score. I even asked him (via comment) if I'd been downvoted because my answer wasn't his and got affirmation. Additionally, another answer I'd written was downvoted at the same time he answered with the only other question (question is 2 months old). Again, there was nothing technically wrong with my answer — it actually contained the same information as his answer.