Not easy to watch that!
Thirty years or so back, one of my RAF colleagues (a navigator) owned a Renegade Spirit biplane powered by a Rotax 2 stroke which had become very difficult to start. He tied the tail wheel to one of the hangar door supports while he worked on it alone. I think he eventually flooded the engine with fuel so he opened the throttle more and more while he pulled it through. When it suddenly started, the tail tie down broke and off it went across the concrete. He grabbed the wing tip but after a few rotations on the ramp he realised it was getting away from him. He let it go as it was pointing away from the hangar whereupon it ran onto the adjacent grass, nose over, stalled the engine and broke the prop.
I think he sold it not long after that because it wasn’t the first time he had badly frightened himself with it. The first time was when he managed to inadvertently flick roll it after unstrapping whilst trying to remove a badly stowed object jamming the control column at low level. He only just prevented himself from falling out over the clubhouse at Popham!