My uncle died pouring gasoline on a brush fire. Yes, I guess it was a stupid thing to do. The fire traveled up the gas stream and hit the gas can and exploded all over him. He did stop, drop and roll, but the fire was too strong and he burned to death.
As for your uncle ... I intend to honour his memory, and the memory of others like him, by NOT pouring flammable liquids on fires. It's tempting sometimes, like when it's cold and the grill is slow getting started, but it's still a bad idea.
The fire traveled up the gas stream and hit the gas can
Yep. That's the usual failure mode. Professional brush firefighters use a firecan to set backfires ... the fire can has a flame arrestor and uses heavy fuel to prevent explosions.