I did not see the under car camera. Generally any agricultural racing will shear off sheet metal fairings, fibre panels etc., but NO GOOD design has fuel lines or brake lines exposed BELOW the frame/tubes of the body.
If 'they' had fuel lines running below (essentially on the bottom of the car) the 'frame', then they had idiots in fabrication.
When you go off course on a turn, you may encounter some moderate curbing, and you will get in gravel, sand and dirt, but NOTHING should be able to reach your fuel lines.
These 'lessons' have been learned over years of racing. There was nothing new to demonstrate and learn here. "they" may have made erros in design and fabrication, but these Corvettes have run in American LeMans for years (prior versions). These guys KNOW how to build a safe, legal, reliable and fast car.
The lesson may be that the corner workers in practice sessions, particularly the first responders MUST have adequate fire protection to perform rescues and extractions. I don't care if it's hot. It's hot at Sebring and Daytona, and we ALWAYS wore the right gear, even during practice.
So ... Did Jr. not really know that he needed to kill the fuel pump after a crash? (there's a swith on the dash)
Did jr. not kill the master electrical switch? did the corner workers not kill the master? probably would not have mattered since the leaking gas was gonna ignite on the exhaust anyway.
Most likely scenario to me is that the crash, caused by an over-exhuberant driver, caused the puncture of the fuel cell, and the leaking fuel was ignited by the exhaust pipes. That severe of an impact hurts and leaves you stunned, but not badly so. (been there, done that) Jr. was busy radioing his status to the pits when he noticed the FIRE!!! urgency set in - he undoes his belts, cool suit and radio connection and tries to get out FAST becasue he's starting to burn and it hurts. As a prior post noted, the heat of the fire does not burn you from direct flame contact, convection or radiation, but rather becasue it heats your sweat to steam REALLY FAST. At least not right away do you burn from heat conduction/contact. A three layer suit will give you about :45 second of life protection. I hope he wore a three layer. Also, what scares the living @#$$@# out of you is that you are breathing hard anyway and the air you inhale is REALLY hot and stinks (been there, done that too). Drivers can die from lung burns faster than skin burns. So jr. is tryin his best to get out of the car (which isn;t all that easy under normal circumstances,) so it looks like he fell etc., but I'd attribute all that to the combination of haste, help from the workers, and adrenaline.
No disagreements here on the Vette's design or construction. I did not intend to knock anybody involved regarding any aspect of what happened, just suggested that an incident involving a well known and well liked driver may serve as a wake up call to review safety procedures.
I must respectfully disagree with your assertion that "there was nothing new to... learn here." There is always something; equipment, training, procedures, or what ever. As you suggested in the following paragraph, better equipment and preparation for emergency crews may be needed during practice sessions. Or (as you implied later) maybe drivers who do not race in this type of car on a regular basis should have more extensive safety training.
You are clearly very knowledgable on this subject and I appreciate your sharing that with us. I only ask that you keep an open mind regarding lessons learned.