:pistons because they must've thought they were in an interference engine. :notice the spot on all the intake valves where they hit and notice how they dont seal at all.... humm non-interference? : :
Hmm that must have obviously been caused by the sudden rush of air coming into the engine when it suddenly stopped and the rush of air had nowhere else to go so it bent the vavle open to escape........... It just couldnt be from the pistons hitting them