Greed is much more common than sabotage. Everyone at every level of production uses 3rd party materials and counterfeit has the potential to be cheaper than non-countfit.
Defense contractors generally pay about 10% less than market for any given service, so I don't discount the possibility that my hypothetical technician may have stolen the goods in order to get some extra money. A poor financial situation is easily the most common motive for the direct perpetrators of espionage.