Back on Mystery Man again, I've looked at some more photos from different angles and I think he may indeed be Jon Rubinstein after all. Ignoring the hair and beard and looking at facial features, bone structure, and especially the ears, I'm about 95% sure it's him.

>>755 It's such a shame the only available reference photos are completely hairless but there's been a remarkable transformation if it is the same man. I too see similarities in his face shape and obviously it makes the most sense if it is him. It's logical that micromanaging stepped in during SDCC and has not left his side for one second since.
In the time between his managers last official press shot he has had the 'stein' chiselled off his nose and his hairline sewn back in- all very plausible in the world of Hollyweird I guess.