Supreme Court of Canada  1 S.C.R. 306
This case was delivered on the same day as Derrickson. In Derrickson, the Court decided that a provincial law about family patrimony could not apply on reserve.
Here, the Court refuses to make a distinction between occupation and possession of these lands in terms of patrimony, and again refused to apply the provincial law.
Is provincial family law concerning interim occupation of the family residence during divorce proceedings valid, applicable, operative and in force when applied to a residence situated on a reserve?
No, a provincial law cannot be enforced when it comes to the occupation of the family residence on reserve (unanimous decision).
Between : Pauline Ester Paul
And: Edward Gordon Paul
Interveners: Canada, British Columbia and Quebec
In 1966, the parties, both members of the Tsartlip Indian Band (Salish), married. In 1968, Edward Paul acquired a certificate of possession for lands on the Tsartlip reserve. A house was built shortly afterwards and became the family residence for the couple and their three children.
In 1982, the couple separated for a time. Pauline Paul kept custody of the children and asked for interim possession of the matrimonial home according to the Family Relations Act of British Columbia. Her petition was granted but the couple reconciled shortly thereafter.
In 1983, the couple separated definitively. After their separation, Pauline Paul petitioned a second time for interim possession of the family residence.
The Derrickson case states that the provincial law does not apply on reserve.
Pauline Paul: Temporary occupancy should be distinguished from proprietary interests. Therefore, this case is different from Derrickson. British Columbia and Quebec both intervened to support Pauline Paul’s arguments.
Edward Paul: There should be no distinction between this case and the Derrickson case. Canada supports him.
Supreme Court of British Columbia (1984): Pauline Paul was granted interim possession of the home pursuant to the Family Relations Act. The trial judge distinguished this decision from Derrickson on the grounds that the exclusive occupancy of the family residence for a defined period does not affect the title to the property held by Edward Paul. There is a distinction between possession and occupancy.
British Columbia Court of Appeal (1984): The Court (in a 2-1 decision) reversed the judgment, claiming that this case was not distinguishable from Derrickson.
Dickson, Beetz, McIntyre, Chouinard, Lamer, Le Dain, La Forest
The relevant section of the Family Relations Act of British Columbia is not applicable to the reserve lands.
Occupation and possession are similar concepts, occupation being a part of possession. There is a direct conflict between a federal law (the Indian Act) and the dispositions of a provincial statute (the Family Relations Act), and according to the doctrine of paramountcy, the federal law has to prevail.
See Derrickson for further information.
Derrickson v. Derrickson,  1 S.C.R. 285
McIvor v. Canada (Registrar of Indian and Northern Affairs), 2009 BCCA 153