From the excellent "The irredeemable Frank McCourt" by Jon Weisman at Dodger Thoughts:
Speculation is that the last straw for Selig was a reported $30 million personal loan that McCourt received from Fox that was believed to be necessary to meet the Dodgers' payroll obligations -- the latest indication of how fragile McCourt's financial underpinnings are.
From "Dodgers' status could remain in limbo for foreseeable future" by Bill Shaikin at the LA Times:
There was no last straw for Selig, according to the parties briefed on his decision. "It was an accumulation of everything," one of those parties said.
Which is it, guys?