i've had tails fall off sometimes. sometimes the tails develops cracks when the rodent is frozen, sometimes the impact of the strike and/or coil or pulling from tongs like a tug o war breaks the tail. heat won't break a tail IMO. i know which snakes are my aggressive heavy hitter/eaters and i'll hold a rat by the leg with my tongs for a more sure grip.

lol i usually feed broken tails to my milksnake as a snack after.