Depends on what happened to it. If the rotors somehow met at high RPM it could happen, but most of mine failed at the coupling, and its a sealed system, so no worries there.
In regards to the debris...remember that little rectangle box thing hooked up to them big ol' IC tubes ya got there? Thats just one big filter. It gets clogged, but it will stop any large harmful debris from entering the engine.
...oh and i think it helps cool the air or something too.