Okay I was not clear.

What I'm saying is, if she had signed a contract to purchase a refrigerator when she was that drunk, the contract would be invalid because she was not "mentally sound" (e.g., she was too intoxicated to know what she was doing).  Contract law says that you have to be "mentally sound" to enter into a contract.

In effect, the judge's ruling says that you can be too drunk to buy a refrigerator, but you can't be too drunk to consent to sex.  Which is absurd.

And it does create a legal precedent. Past cases are looked at for guidance, so that the "law" is applied consistently.  Past precedent is one of the foundations of the way the "law" is applied in Canada, so this case has major implications.

The CBC has a much better story on this case by the way. Including the facts that the cab driver in question has had prior allegations of sexual assault and misconduct.