The taxpayer, which was a U.S. corporation with a mining operation in B.C., was prohibited by s. 18(1)(m) from deducting royalties payable by it to the Province of B.C. notwithstanding the provisions of the 1942 Canada-U.S. Income Tax Convention which provided that in determining the net industrial and commercial profits of a permanent establishment there shall be allowed as deductions all expenses reasonably allocable to the permanent establishment. Hugessen J.A. stated (p. 6197):
"The interpretation proposed by the appellant ... would have the effect of giving a U.S. taxpayer with a permanent establishment in Canada a more favourable tax treatment than its Canadian competitor engaged in the same business in this country. Such a result would not be in accordance with the policy expressed in the preamble to the Convention ..."