I have never worked with explosives or done destructive testing, but there is an earlier mention here of how an internal explosion can bring down a plane.
Supposedly the explosive that brought down the Lockerbie plane was only about the volume of 3 golfballs. It didn't explosively destroy the plane directly, but the shockwave from the high explosive detonation overloaded airframe components to failure. Then cascading failures of the pressure hull did the rest.
A small explosion near the tail might have the same effect on the RPB. If so, loss of the tail would quickly destroy the aircraft.