The full purchase price of $100,000 for the acquisition by the taxpayer of seismic data represented Canadian exploration expense to him notwithstanding that $85,000 of the purchase price was satisfied by a promissory note for $85,000 which would be paid down during its term out of a portion of cash proceeds received from any future sales or licensing of technical assets and of production cash flow generated from petroleum rights from drilling programs. The note did not represent a contingent liability because it provided that should any amount be outstanding at maturity, the holder of the note would have recourse to specified security (in such event a trustee was to be appointed to sell seismic data with the proceeds of sale being allocated as to 60% in reduction of the remaining amounts owing under the note). Rothstein J. stated (at para. 33):
"The Minister seemed to be saying that if there is risk to the value of the collateral security at maturity, liability is contingent because the creditor may not make full recovery of the total liability. If the Minister were correct, all liability would be contingent."