The night shift "borrowed" the bolts to use for a different satellite, which they simply should never have done. There's no proper place to record it, because it's never a proper thing to do. They also didn't notify the day shift in any other manner that they'd done it.
The day shift came in and failed to perform any verification that everything was in place before starting to tilt the satellite. Sure, they'd followed the procedure for installing them, torqueing them right, and whatever else was called for. All the same, after leaving it and coming back the next day, one does a walk around and visual check that all is well, which they did not.
The blame goes 80:20 against the night shift.
I was working for the commercial division of Space Systems, in Newtown, Pennsylvania. Even though it wasn't our bird, it was still a bad day.
The one that was our bird was a commercial com sat, AMC-4. Those were designed and build in two places. The outer panels, where most of the equipment resides, were designed, assembled, and functionally tested there in Newtown; the core structure, where some equipment including most of the propulsion system resides, was constructed and functionally tested in Sunnyvale. Then our part was shipped to Sunnyvale where the two pieces were mated and went through environmental testing. And I'm leaving out a bunch of details.
The fully integrated satellite was bolted to the shaker table where vibration testing is done. The hydraulic cylinder on one corner developed a tiny leak inside the rubber boot, putting a mist of aerosolized hydraulic fluid into the volume inside the boot; no one could have known it was there. And no one knows where the spark came from. It blew out the cylinder and dropped the satellite several inches to a hard landing, but the bolts held and the satellite remained upright. The person in charge was a friend, a temporary transplant from Newtown. After a lot of analysis and negotiation with the customer, we agreed on a plan for extra inspections and tests. Ultimately it launched on November 13, 1999 with a planned 15 year mission life, and is still operating.
Ah, those were the days.