For one of the aircraft mentioned in Skunk Works Lockheed insisted on doing the maintenance themselves because the military maintenance folks were making mistakes causing aircraft failures.
This incident is a data point in the "right to repair" where Congress is trying to force defense contractors to make all of their equipment entirely maintained by DoD workers, apparently they make mistakes though because in this case it is the stupid failure of a significant portion of the hydraulic fluid being water (which is a problem you could cause in your car but don't because you're not foolish and you put in the correct fluid and don't just fill your radiator up with water)