People are so quick to judge. I guess it's just easier to blame a referee for a teams loss instead of themselves. Referee's can make as much errors as the players do on the field, we are human arn't we!
But the main focus here shouldn't be about mistakes that referees make, if it were.... the holden half-time would have a summary of all the missed penalties and knock-ons that the ref made instead of the teams errors and missed tackles.
It's how a team deals with the decisions made that makes the difference between winning and losing. If a team has an attitude where that they feel that all the penalties are going against them for no reason at all, they're going to become frustrated and sink into quicksand (for those that have watched The Replacements with Keanu Reeves would know what that means). A team that accepts the decision, deals with it and just plays the game, will overcome these "bad decisions" that are made and will often be rewarded.
Teams that burden themselves with decisions that they can't control are going to stuff up the part of the game that they can control. Referees do the same, they ref on what they can control, and don't let the things that they can't control get to them.