First things first, Happy Birthday!!
K_1269: Please don't downvote people in my giveaway for participating! If something bothers you, blame me ( it's because of my rules afterall).
A little late for that, I'm afraid, but there's also a matter of principle involved. Whatever the failings of your system, you're a very generous and good-intentional host, utterly beyond any critique. Moreover, I wouldn't blame someone for merely participating in your giveaway.
The case here is quite different, however: in their haste and negligence, mrbax screwed over another person, plus the person who previously and diligently nominated them. Now, it's one thing to negligently screw yourself over, quite another to sabotage someone else, and worse yet if it was done for personal gain, i.e. posting their wishes. I won't even entertain the possibility that the sabotage was done on purpose, though none of the evidence precludes it.
So, in observing all this, I felt quite justified in issuing a single, inconsequential -1, and then openly stating my displeasure, as is proper. In the scheme of things, this is entirely harmless. Ironically, if I did wish to actually harm their chances, I could do much worse: enter for them, invalidate their entry, and it would all be within the rules of the game. Which then makes me curious: would you allow someone to sabotage another's entry, knowing full well it was done with malice and intent, yet entirely within the rules of the game? That would be a nasty task for a birthday gift, no?
Of course, I won't be doing that (it's worth remembering, though: I could have). No, the choice will be entirely with you: will you follow the rules of your giveaway to the letter and allow a hasty, reckless poster to eliminate a selfless and deserving one, all the while getting his own name in the hat? Or will you bend those rules and not let people's careless avarice sink the chances of their more considerate peers? Remember: it's your giveaway and you, not your rules, have the final say. Good luck, and again, Happy Birthday!