It was very sad about the DJ incident.

But if my facts are correct, i believe there was nothing more that the marshals could have done with the time factor between the engine blowing on a bike and dumping oil on the track and DJ arriving on the scene on one of the fastest parts of the circuit, which i believe was seconds rather than minutes.
That was just a terrible racing accident, which the marshals could not do anything about. By the time they got the flags out, which would have been a few seconds, David was arriving on the scene.
Remember during the 1980s, when a horse got scared by the air ambulance, landing in a field near Sulby Bridge, to pick up an injured rider.
The horse got out onto the track on the approach to Sulby Bridge, and before the marshals had time to react, which again was seconds, a rider arrived on the scene, collided with the horse killing himself and the horse.
In my opinion, these are freak, and very rare accidents.
Possibly with just whats gone on with the recent inquest, volunteers could become very afraid and reluctant to be marshals, and not taking on this responsibility, unless they are fully protected legally, and as we all know, if there is no marshals, then there is no racing.