A random Reddit post by an anonymous internet user? Hardly confirmation.
His Reddit username is his real name and the value of his post (the confirmation) is in the image he links to: http://i.imgur.com/zD1S8y6.jpg
Everyone at the premiere wore these. The staff had yellow-bordered badges and the guests had red-bordered ones.
I suppose he could have forged it, but then he would have had to do it in a very short amount of time and he would have had to have access to a real one.