Precedent is hard to change, but it can be done by the courts. Parliament, as the sovereign law-making body, has the power to override any common law precedent.
A judge may find a fact in a particular case that is different from the one that set the precedent. Because of this fact, the court is not bound to follow precedent , as the facts are different.
E.g. Davies v. Waldron (1989) and Gillard v. Wenborn
The defendant had been found guilty of being in charge of a motor vehicle with a blood alcohol concentration above the limit. He was found sitting in the driver’s seat, with the keys in his possession and had started the engine. He argued that the judge show follow the precedent set in Gillard v. Wenborn, where a man was found intoxicated and asleep in the front seat of the car, with the engine running. This defendant was found to be not guilty. The judge, then, distinguished Davies v. Waldron from Gillard v. Wenborn because the first was found starting the car, and the latter found asleep.
When a superior court decides not to follow the decision of a lower court, precedent is overruled. The same court can also overrule any past decisions it made.
e.g. O’Reilly v. Commissioner of State Bank of Victoria (1982) and Baker v. Campbell (1983)
The High Court decided that the ATO could compel the production of documents protected by legal privilege, which was later overruled in Baker v. Campbell, and that legal privilege is an important right. The change in viewpoint could have been caused by changes in the composition of the court, i.e., if a judge was replaced.
When a case is taken to a superior court, the superior court may reverse the judgement, and this becomes the new precedent. Reversing only occurs if the case is the same.
e.g. Norris v. Sibberas (1990). A couple bought a motel on the advice of their real estate agent, who said that they would make a lot of money from this busy motel. However, the motel did not earn a profit, and they went bankrupt. They sued the real estate agent.
In the District Court of Victoria, the judge followed the precedent set in Shaddock v Parramatta, as the agent did not disclaim responsibility and she was setting herself up as an expert, so she owed a duty of care to the buyers.
On appeal, the Supreme Court reversed this decision; the agent only owed a duty of care in which her expertise lies. In their obiter, the justices added that the couple should have known that the estate agent was not an expert, and should have relied on someone who was an expert, like an accountant.
This occurs when a precedent set in the same level, or a higher level, is followed for the sake of consistency, but the trial judge expresses disapproval about the precedent. Essentially, it means that the judge is bound by precedent, but says that he believes it should be changed, by Parliament or by a higher court. Mason, J. stated that there are powerful reasons for the court to be reluctant to engage in changing the rule; such law-making should be left to parliament.
e.g. SGIC v. Trigwell (1978)
The Trigwells were injured when their car collided with another one after hitting two sheep, and sued the owner of the sheep. The High Court decided to follow the precedent that the landowner did not owe a duty of care for their stock straying on roads. In 1984, the Victorian Parliament passed the Wrongs (Animals Straying on Highways) Act, which abolished the common law and made the stockowner liable for negligence.