It's one thing to monitor a race from a track such as Phoenix International Raceway where the entire track is clearly visible. It's quite another to have full course monitoring on a street venue such as that in Prince Albert Park in Melbourne. When a car disintegrates in a collision there are large parts and small parts. Even with tethers, wheels separate from the chassis. Wings and body pieces fly through the air.
Carbon fiber is like shrapnel.
In countless races, this disintegration takes place without any injury to racers, track workers or spectators. In the Australian accident, spectator injuries were so minor no one had to be taken to the hospital. If the marshal had not been at a gap in the fence, put there so that marshals can quickly access the track, and if the wheel had not been on a trajectory through the gap, he would likely be alive today. It was a freak accident and likely one that won't be repeated. T here are additional safety improvements that can be made.