That is in no way "clear evidence", the opinions of all the Youtube commenters notwithstanding. It can just as well be explained by the rotation of the rear wheel, see for example https://youtu.be/aN7HjwZI-k0?t=32.
It looks like the bike comes to a rest with the tire in contact with the road, presumably stopping the rotation of the wheel. Then when the cyclist lets go of the bike it takes off.
https://www.youtube.com/watch?v=ynLMfzLTc8M
The cyclosport officials intentionally hide/enable the problem for years.