I have seen the full video and spoke to the production guys.
Turns out that the bike is actually tow launching the 300.
It is hooked up via 30lb fishing line with the drag set.
They were testing the 300 as a platform for a gyro and the biker was still hooked up and forgot & was heading home for the day.
It all seems very calm here but you should see what happened when he got home to his garage.
HF