I listened to David Locke's podcast and he basically dismisses the Deron Williams trade rumors because he says he doesn't trust the info Marc Stein tweets. As smart a Locke is, he's actually stupid sometimes. It was Tim McMahon @ ESPN that reported the D-will/Jazz rumors.
If you read teh Tim McMahon story, it was credited to both Stein and McMahon. McMahon just runs the coverage for Jazz/Mavs so it's probably his news to leak even if it came to Stein first.