The bolts that hold the prop on are a red herring in an incident in which the prop came off? The bit to which they were bolted, and whether they were correctly bolted to it, may not be.
I still don't get why the removal of the apparently very important piece of evidence resulted in a bolt that has a washer and nut on it, some bolts with a washer remaining on them and some bolts with neither.
All very odd.