Look at the shadows of the PD vehicle, cop, the trees/shrubs and the vehicles moving in the same direction the bike was traveling......and then the truck’s.
For the bike to have collided with the truck, the car would have had to keep on going after watching the bike & rider go down directly in front of him. It's possible, the bike was all the way on one side, the rider on the other, but unlikely with a cop right there.
Or, either that car (again, unlikely) hit him or another that was crossing perpendicular to the bike and either behind the truck or crossing 180 degrees from it, which would have put it 10 feet farther from the cop's camera, and 10ft closer to the bike.
If it was a short car, the shadow probably wouldn't show up on the camera.
I still don't see why the cop doesn't show any interest in any vehicle - unless he called it in when audio is out, caused accident himself, or the rider washed out his front end, swapped ends or went straight over the bars like the Yamaha in Martin Fierro's clip.
I bet he'd feel pretty stupid if he was practicing stoppies in front of a cop, and I've seen worse, but I doubt it.