Gotta assume mrmo has never even been there nevermind ridden the section of track in the video in which case it’s probably best not to comment.
No I haven’t been there, seen plenty of similar situations, but the point is simple, and as garage-dweller points out, you don’t know whether the rider before has crashed. There are reasons why you have marshalls, If you know the track is clear then fine, but if you don’t and can’t be sure then…
People are idiots, and will do stupid things, it is one of those life lessons you learn, sometimes the painful way. Rider made a judgement that the track would be clear, it wasn’t.
Now get HSE involved and what are they going to say about a purpose built track, no marshalls and no control over who uses it? Where are the risk assessments, the evidence of training/compitence etc.