I was running against the AI in a GTR2 race at Zolder & right before the center of T3 the Porsche in front of me hit something invisible, came to a dead stop, & went airborne causing a huge wreck.
I also noticed this in a WTCC 2015 race where two AI cars crashed in the same place. I think the mesh is broken between those rumble strips because you can clip right through the ground there with the free camera.