For a kid who allegedly stole 10 bucks while sitting in the car waiting for his mom and was confronted about it minutes later you are giving him a lot of credit for his deception skills. Ha ha maybe I am too naive, but this is how I interpreted your post: Money is missing, confront son, son denies, son empties pockets-no money, son is questioned and still denies,....I think possibly your son knew that this would not be dropped with simply him denying it... no-win situation for him. You call and continue asking about the money and maybe, knowing you would take the video cord, his friend agreed to give him money because he knew there would be consequences. Thinking Aspie-like, he saw the problem...(which to him was likely loss of video games)...and he solved the problem (in his mind) by paying you the money you wanted, even if he didn't take it.
Obviously, I could be way off on this, but I do tend to take a kid's perspective, especially our spectrum kiddos~