Whenever CRA has investigated my clients re: T776 they have been very lenient. As long as the client could provide some reasonable explanation for the expense, as well as receipts or other documents to prove the taxpayer incurred it, CRA mostly allowed the deduction, even if it was something questionable or not typically allowed under the ITA.
That said, I don’t count on that leniency. Often I tell clients to expect CRA to disallow certain expenses, and expect to pay some tax (and penalties/interest). Then, we are all pleasantly surprised when CRA allows more deductions than expected.