Forum:Rebel Spies on Endor before the attack?

I hope that this hasn't already been discussed, but it seems that it hasn't. Anyway, I was watching Return of the Jedi and I noticed, for the first time, that in the scene where the Imperials have captured the Rebels, there is a surrendered man in stormtrooper armor who is no longer wearing his helmet. I was just wondering if anyone knew who this was, why he was in stormtrooper armor, and whether there is some reference to him in Star Wars canon? This has been bothering me for a couple of days and if anyone has an answer I would be greatly appreciative. I have tried searching for him, but I have failed to come up with an answer to this question.