Here’s the GAO press release. (PDF)
What I think happened is that the Air Force gave the contract for building a new refueling tanker to Airbus, which was going to build it in Mobile, because Richard Shelby was doing his thing. And then the Democrats took over Congress and Washington’s delegation did its thing, plus the economy went into the toilet, as did the dollar, and the government was looking for a way out. But this may be unduly cynical.