I agree with malc -
The buck stops with the rider.
It's that simple.
Now you all know by now - when you decide to ride a bike you take full control over every possible or emerging scenario. And then some others too ! It's no use crying about gravel, diesel, bits falling off trucks, people pulling out, etc.... Those things will never stop - so it's down to the rider to be able to ride defensively/ suitably and apply appropriate roadcraft. (For some people this is difficult - because it MUST always be someone elses fault ...)
I've watched many many people get their knee down on the island and the exiting "chicane" in question and I've always marvelled that no-one crashed there before - because the surface is very poor. It's both shiny and cracked.
(And - it's a major potential for diesel too, as this is a major road for HGV's).
Only a fool would try and get right over on this exit.
As for the spectators.... - yes it has been getting increasingly worse for a long time. On fine evenings, it's just teeming with hordes of people. There's been times when it's difficult even to park a bike !! Even moronic parents bringing the children right up to the roadside for a good viewing. But nobody deserves to die for being daft enough to watch our foolishness on bikes (ridden well or not).
No doubt all the facts will come out in due course - but don't try and make out any rider isn't responsible for his or her actions.
(PS - I was involved in 2 fairly serious bike accidents so far. Technically, neither were my fault. Years later though, I know I could have avoided them if I had applied proper roadcraft and improved observation).
As they say - it's no good being in the right and dead !