Same here. When I replaced the gaiters on my trad Plus8 there were locking tab washers used to secure a couple of bolts. Lock wires could be an alternative. Threadlock another. QA procedures should have "tell-tales" such as marker pens, paint spots etc as visual indicaters. Mass production assembly lines use purpose built assembly tools with built in pass/fail check systems with regular calibration checks. I doubt MMC have much in a similar way but should have a strict procedure for safety critical assemblies, basically attempts to prevent human error as a factor. Poke Yoke is a Japanese term for " idiot proofing" an action/assembly. Hence designing in features that make it impossible to incorrectly fit items by having one orientation location fit lugs/tabs/pins etc. A bit like the spinners for centre hubs. Left OR right hand with appropriate markings. As DaveW says, what is the reason for failure if correct assembly was done? Was it correct or a tick the box " check" not actually done? If so then there is a gap in QA.
