For your reference, here's the relevant part of the law:
https://laws-lois.justice.gc.ca/eng/acts/I-2.5/section-127.html
The key part being "No person shall
knowingly (a) directly or indirectly misrepresent or
withhold material facts ... (b) communicate, directly or indirectly, by any means, false or misleading information"
I bolded the 'knowingly' for emphasis as well as withhold. Where the lawyer comes in is that "knowingly" is slightly different than 'intent' (a common term with centuries of precedent for criminal law at least). I'm not going to opine on the difference, surely there is also case law and precedent. And of course the other part -
withholding material facts is also salient.
But I'm quite certain there is either a legal definition or case law/precedent/practice that covers a case such as yours. And clearly the law and practice are NOT designed to capture nor punish cases of, for example, clear typos (or neglecting to select the right drop-down box on a form). And in addition, you did not 'withhold' the fact of your previous refusal, since you disclosed it elsewhere (and I bet a lawyer would dispense quickly with the 'misrepresent' term here on the same basis).
This is actually a fairly simple matter in some respects, but still - a lawyer will be well placed to put this properly in context in as strong a form as possible.