That information probably came from the LADWP official, Lou Flung Poo.
Spokeman Flung Poo said consumers cut back on their water usage so much, the pipe just went limp and collapsed on itself.
Today, they said they had to shut off water slowly because of concern over changing pressure in the pipes. But it could certainly be another BS story to weasle more money from the tax payers. I have no idea-just posting something I remembered from previous coverage of breaks in the system.
(Like you said-perhaps they were arguing for 4 hours over which way to turn the valve :-)