This answer of mine got accepted several minutes before it got the first upvote. Yet, I did not get the Naruto hat. Is this a bug? I suspect it's not since others have gotten this hat, yet according to the description, I should have gotten it.
This is not a bug as description of Naruto hat on Winter bash page says.
Post an accepted answer that receives no other votes for $12$ hours
And according to your reputation history and statement in question your answer was up-voted within few minutes.