I'd just write them a letter with the van number, time and place it happened. Be sure to mention he pulled into the McDonald's right after (maybe it was a time he was supposed to be working not getting food). I don't think you should try to imply that it was deliberate and it may not have been. There LAB used to have a nice video, Bicycles and Trucks Sharing the Road but unfortunately it doesn't seem to still be available. Maybe there is something else like it out there you could share with Comcast and suggest they include it in their driver training. Sure, you want this guy held accountable, but why not use this as an opportunity to try to get Comcast to get the message out to all their drivers?