poor chap
Sounds like the problem area is the gravel section to the side of the normal start and finish straight. This bit of track can be seen near the control towers shadow on the image in the web site page linked to in post 1
I guess this explains why they'd fenced off a big section of the spectator area at that point of the track, for the event in 2013
"motorsport is dangerous, so you are present at your own risk" from a legal stand point, even though they made a change to the circuit route, i cant understand how they can ignore this, those notices would have been up and the same thing on the guys admission ticket
you can still be pelted by gravel if a car goes off, at clearways for example, you learn to turn away