I saw this over the week end. They claim it is real. i believe it is....well sort.
The trucks are not running backwards but the film is. Note that the drivers are not viewing their rear view mirrors.

If he startred out with the split, and the trucks came closer together as they moved forward, he could safety press againt the sides and compenste against his weight as it raised him up.

Going down against a spreading foot hold, traveling backwards, would be tenuios at best.