It certainly seems he did break his own rules however there is still a chance that all this will be cleared up and the OP of that thread will make the payment to the winner or better still he can clarify why he did what he did and then re-run the giveaway but announce beforehand how he intends to select a winner. As long as those things happen he can have credibility but the way it turned out it seems very inappropriate.
The problem is that, so far, since the winner was announced, OP was not online anymore. I don't even know if he read what was written at the end of his topic (meaning the posts signaling that was he did is totally inappropriate). Besides, no matter the incompetent way he managed the giveaway, he also did not pay the prize to the (fake) winner. This is winner's address: 1MxqUhnCwuUwbc7Z1NhNTTGiVHJXBpurCi; I am constantly monitoring it since this user was declared as winner.
So there are higher chances for OP of being given negative feedback for not paying the prize than for poor management of the giveaway.
Someone suggested earlier this could have been an attempt to get merits and try to build up the account which for $50 would probably be worth it if he could get merits. Having said that, there is a chance this could all be a misunderstanding and could be resolved (but I have reservations).
Who knows... Maybe he expected the merits when he announced the winner and, seeing that he still does not receive any merit he decided to go offline, knowing that it's possible to have the account tagged? Anyway, let's wait for a few more days and see what happens meanwhile.