Over at TOS, OKCS claims there's a security tape showing a second person sitting in that Ryder truck. Not enough clarity to positively ID anyone; but, enough to see there was in fact other people involved.
There's always a motive to any cover-up; &, this is no exception. But people (like me) have no choice except to watch this play-out through the work of others.
...& patiently watch as fate takes its course, right?