Breaking a Fixed Joint With an Impulse?

I have an object connected to the world with a fixed joint. When I detonate a bomb next to it, I use Rigidbody.AddExplosiveForce with ForceMode.Impulse to add an impulse to it for a single frame. The fixed joint breaks, but the rigidbody gets no momentum from the impulse. It simply drops to the ground due to gravity instead of getting rocketed away by the impulse (even if I set the impulse to be a very large number).

I would think that if you break a joint with an impulse, some amount of energy would be lost to break the joint, but the rest of the energy should be transferred to the rigidbody.

Is this an engine bug or a design decision? If it is a design decision, what is the reason for it?

 

Is your object particularly heavy? forcemode.impulse considers mass. If you destroy the fixed joint just before the impulse is the object actually pushed?.... just a thought.