just saw the mov of the flashback experiments done by the naked whiz and posted on his web site.
AWESOME!! that is a better demo than ive seen at any fire fighting school (ive been to 5 different ones).
the mechanics are much as you found out..hot fire, close the lid, fire consumes avaiable oxygen, plenty of heat (which still drives out gasses from the fuel). the fire is only subdued, not dead and it is hungry for air. always vent before opening just like the fire departments do (break windows, cut hole in roof). this allows the hot gasses to escape and you get to keep the hair on you arms.