Becky, Sam,
I had something similar happen many weeks ago when everyone was still on the V patch. After a track change there were two of us. My connection display showed the other player, but I didn't see his car on the track. The race started and everything seemed fine except that there were no barrels where I normally expected to see them.
As the race progressed, I saw that the other driver was turning in Fastest Laps. He also lapped me but I never saw his car. After about 2 laps I say his car flying through the air. It wasn't from a crash; the car appeared to brake and turn normally, but it was up in the sky. The other driver saw the same thing.
I figured it was just a server screw up. After disconnecting/reconnecting everything was fine. I didn't grab a MPR and didn't think of mentioning it since the problem fixed itself.