J.L. Guay Ltée v. MNR, 71 DTC 5423, [1971] CTC 686 (FCTD), aff'd 73 DTC 5374, [1973] CTC 506 (FCA), aff'd 75 DTC 5094, [1975] CTC 97 (SCC) -- summary under Certainty

Nöel A.C.J. stated (at p. 5427) that in order for an accountant's report to give the taxpayer a general picture of his affairs "it is not necessary for the profit shown to be exact but it must be reasonably close, while the Income Tax Act requires it to be exact, and it is thus necessarily arbitrary".