In the shape of things the load that a thread exerts to punch a hole like this in a non-load bearing alloy cover are probably not that great. It is a crankshaft nut that will have some mighty axial load thrust bearings on an engine like this I am sure. It's a good robust engine but it's assembled by humans, just like the rest of the car, so things may go wrong now and then. Poor assembly I can manage but bad design.....
