In the cold light of day I have re-analysed the OzV Scots 1/4. My 1st point is the Australians played this a lot looser than the group games, maybe their phsyci told them this would be easier than their group games so they played in a less structured way, this led them to score 5 tries to Scotlands 3 of which one was an interception try and another after a bad clearance kick was charged down, so although Scotland ran them close on the score board in real terms they were along way off and had Oz lost it would have been because they gifted it to Scotland, something they will learn from.
Rather than blame the ref as Scotlands fans are doing I would thank the Australians for allowing you to have hope almost till the end.