I'm not sure. Why do you think this would be assault? I'm not familiar with Canadian law, but article 265(1)(a) defines assault as without the consent of another person, he applies force intentionally to that other person, directly or indirectly; I'm not sure that performing a physical examination under false pretenses is 'applying force'.

There may be Canadian case law clarifying this, I don't know, but prima facie it doesn't seem to me that your position is correct.

Note that other legal systems have problems with doing things under false pretenses. A woman claimed rape because her husband's brother slid into bed with her and initiated sex, in which she went along. The guy didn't disclose explicitly that he wasn't the woman's husband. When she found out she felt (justifiably) violated. Yet the guy was acquitted because there was no statute on getting sexual favors under false pretenses (there is now by the way, as a result of this case).