I don't care if you’ve done it without incident 100 times that does not show it is safe.
It only shows is that you can be 86% confident the failure rate is 1 in 50 or less.
You don't necessarily have to do it each time without incident (although this would be ideal) but you do have to make sure that you have prepared for these possible incidents.
Why use flammable solvent in the demo if you do not have to?
The hazard is high even if the risk, done properly, is low so why do it?
Because it looks cool!!
Having said this though you will be happy to know that we are actually running the demo with water slurries and bunsen burner.
I do agree with you on safety. I also think that if you were to factor in all the possible hazards and outcomes nothing would ever get done. Even in your job there is some degree of acceptable risk being taken by the company. As cynical as it sounds, sometimes it is cheaper to pay out compensation than to prevent the accident in the first place (I don't agree with this by the way, but I am sure that it is factored in by number crunchers all over the world.) Think about your exposure to flammable solvents, what is the safe working limit? who set this limit? are they actually working there or have they just come up with this number so that you feel better about working there.