That video reminded me of an incident I had with my XR75 back in the day, riding at the "Rubber Dumps" in Butler which is now Lowes. Not what you think, lots of scrapped shoe soles, bowling balls and other hard rubber items...and toxic waste.
Going up hill much like that, a vine got wrapped around my handlebar....and throttle.
Now at full throttle, the front end lifts up and the bike is hoisted into the air by the vines.
The rear wheel then winds up in RPM, and when it makes contact with the ground, launches the bike up again.
It kept jumping up in the air in this perpetual state, with the rear wheel buzzing at my legs, the kill switch beyond reach, and took several minutes before I was able to disable it.