So 15 over and 15 under, assuming they were roughly equal amounts on each team O/U Vegas made a killing. They dont care that they were "wrong" by 2+ games on any given team all they care about is there is equal money on both sides.
Vegas does not care who wins and losses (unless there is unequal money on one side which happens since it is almost impossible to get the exact equal money on both sides) They just put out numbers where they think equal money will be on both sides not what they think will happen.