Say you're exhaust exits right behind the cat.

Say you're on the highway cruising at about 120mph for ~10 minutes.

Say you lose spark because your coil wire pops off.

Would all of the air and fuel being pumped into the catalytic converter (due to the lack of combustion and the engine at about 5000rpm) cause it to break apart and shoot out of the rear of your car in glowing orange chunks, about the size of grapes?