Sounds like a classic case of the guy that wins most of the last half of the rounds winning the fight. The scorecards gave the last 4 rounds to Mosely from all 3 judges and the last 5 rounds by 2 of them. Of course I never saw it so I'll have to go by George Foreman's opinion. He's almost always right on the money.
I really think that most of the judges don't actually score the fight as it progresses. They wait until the last round to decide who won the earlier rounds too. I guess it's always gonna be a part of boxing.