Yes, and no (unless the person doing it does not know what they are doing). Knowing which part of the flame is the hottest, and estimating how much heat (not the same thing) it can transfer, and watching the gas flow can allow one to be precise enough to hold that difference in temperature across that distance. It's the same as what makes using a torch to get a cotter pin out so simple, you just make sure the crank gets hotter than the pin.