Optimusprime, the cylinder can only hold as much volume as its size permits unless it forced in under pressure. Any air that can enter through the plug threads can escape the same way, even during the compression stroke.

I showed the mangled plug to the machine shop guy who did the guides, valve job and milling. He said it might be very possible to salvage it without delving into the bottom end if the piston isn't cracked or damaged too badly and the connecting rod isn't bent. He said heads can usually be repaired and he's seen some very beat up pistons that are still in running cars. I'll see when I get the head off again, working on it now, but not much time to do it.
What I don't get is why it would stall and not even sputter trying to restart. The other 5 cylinders seemed fine. Wouldn't the bad cylinder act as if the plug were just fouled and causing a miss? Shouldn't it still run or at least try to run? obviously something else is wrong.