On the video, which one of the men then started to shoot with his cellphone, you can hear a gasp as the two watch the horror unfolding in front of them in what police believe was a possible road rage episode that miraculously killed no one but left one motorist injured.
The motorcyclist and the silver sedan veer together into the southbound carpool lane of the highway. As they do, the motorcyclist appears to attempt to kick the sedan with his right leg.
The sedan veers to the left in response, sideswiping the motorcycle.
But then the sedan driver swerves back across the lane to the right and then wildly to the left. Apparently out of control, it smashes into the center divider.
Sparks or flames shoot up from the left front wheel of the sedan, which then spins back across the lanes of traffic into a white pickup, which flips over.
"Okay stop," says one of the drivers of the car where the cellphone is filming. "Call 9-1-1 Chris," said Tim Morrison.
The motorcycle driver takes off and has yet to be apprehended.
California Highway Patrol officer Josh Greengard told ABC7 that the motorcyclist left the scene and "that is technically a hit and run, but we're trying to get his side of the story. . . . We're trying to see if it was an intentional veer to the left or a reaction veer to the left."
Greengard said the driver of the truck suffered "moderate" injuries.