Is the guy just not loosening the bar nuts, or is he just clamping down without getting the adjuster pin in the bar hole? crud under the cover so it's not tightening proper and just cranking on the adjuster screw to keep the bar forward?
Buying a hundred dollar cover instead of the bolt, etc, would make me want to ask the customer about it.
Maybe someone at HLsupply could call the guy and see how the saw is being handled?