Dude this sounds like trouble. I just went through this and am still rebuilding. Is anything else broken? check lifters above the cam and rods that are below. Is there any debris that may have come into contact with the cam while it was moving? What kind of break and where?
Beware of bent valves as a secondary casualty. If the cam stops moving but the crankshaft doesn't.......somewhere open valves get smacked.
keep us posted!
chris