a popular variation on that is refueling a gasoline drive device, and the fumes drift into the propane water heater. I'm told the flashback can be quite impressive. One of those endless, but impossible to not look at, Oh!!! ... sh ... moments. With a slight whummp as the fumes catch and then the sight of the flames casually stroll back to the gasoline can, and/or fuel tank, you left open.
The resulting fireball is somewhat less well documented. Mostly because those who have seen it, and lived, tend to be focused on extended debridement sessions and hoping the latest round of skin grafts takes.
That said I have to say that carrying a candle while pouring gasoline is a fine way of making an otherwise boring life more interesting. Way more reliable than those pesky propane water heaters. Most of those installed in the last fifteen years or so have been raised at least 18" off the floor. Which tends to reduce their entertainment value. Darn inspectors ... always ruining the fun.