Here's how I think it went down:

Conference Room, Spirit Aerosystems:

"How can we reduce the hours needed to get the fuselages out of the door?"

"We could skip tightening the door plug bolts. After all, they use them at Boeing to finish the interiors so it will actually save them time, too."

"Johnson, get this man a promotion!"

Later that year

Conference Room, Boeing

"How can we reduce the hours needed to finish these interiors?"

"We could just skip removing the door plugs and do it all from the actual doors. Then we don't have to re-do something already done at the supplier"

"Johnson, get this man a promotion!"