I'm not sure anyone can really conclude this. These guys were friends and business partners. This was not their first time participating in car events/charity work together. It's not like Roger was a stranger inviting Paul for a ride. And there is no way to know whether or not Paul was egging Roger on to put on a show for those who came out for the charity event. If that turned out to be the case, are you suggesting Paul is an accessory to his own murder?
It was an accident (whether it could have been avoided or not is another debate entirely) plain and simple and the loss of both lives is tragic.