I think the accomplice angle has little or no weight. It sounds good on paper, but it's just the stuff of conspiracy theories and television.
For starters, it would only make sense if he were doing something that seemed impossible or very difficult to accomplish on his own. Cheating at races is not rocket science. When you combine his delayed start, overdressing/disguise, odd splits and missing nearly all of the photo opportunities, what is there not to understand?
Second, it is rare enough that there is one person willing to go through such extreme and bizarre measures to gain only a slight amount of notoriety. What would be the chances that there are two people conspring together so that this one person can have faster race times? Possible? Yes. Likeley? Not a chance.