I collect allot of autographs and this one looks authentic. I sent him the photo so the only way that it couldn't be authentic is if it would be a auto-pen. On an auto-penned one there are dots at the end of each letter. On this one there are no dots. Also when I sent the photo to him I sent him an index card. One the index card, you can see that the sharpie that he was using was running out of ink. If it was fake, the autograph would be nicer. If you ask me I think that it is an authentic autograph.
Another thing, when I sent his this photo to get autographed, he personalized one to me in the same hand writing. I would think that that would make it authentic.