Dickson, J. made a finding (at p. 477) in which the majority concurred (at p. 458) that a "mineral income tax" which effectively taxed 100% of the difference between the price received by oil producers at the well-head and the price they formerly received before the increase in oil prices following the 1973 energy crisis, was not an income tax:
"The tax is not levied upon net income. It is more in the nature of a gross revenue tax - as above a statutory figure it becomes a 100% levy - that has generally in the past been regarded as an indirect tax. The tax is in essence a flat sum which will vary according to the sale price of the oil but is not necessarily reflective of actual expense experience. Expenses are discretionary and not inherently deductible so as to fall within the definition of an income tax."