No, actually, that's not how the presumption would function. All that the police would have to do is prove that the person lived with or was habitually in the company of the exploited person. Once they've proven that, they've made out one of the required elements of the offence. The expression “exercises control, direction or influence over the movements of a person” was only chosen because it was felt that it best reflected the types of actions that would be involved in living with or being habitually in the company of the exploited person.
So you don't have to prove that actual element of the offence. The related fact is proven; the element is made out. Just to clarify, this is a side issue, but that phrase has actually been interpreted by the Quebec Court of Appeal in a case called Perreault c. R., and it establishes a very low bar.
Even if this presumption doesn't function for whatever reason and the police and prosecutors have to prove in a court of law that someone is exercising control, direction, or influence over the movements of another person, that is fairly easy to make out based on the Quebec Court of Appeal decision. In fact, in a recent case called Urizar c. R., they interpreted that phrase using the Perreault decision.
I'm quite confident that phrase does have meaning in law, even though it doesn't have to be proven for this presumption to function. That's just a side issue since it's come up.