While that is the substance of that particular case the SCC wrote clearly that consent must be given for each sex act, and cannot be given in advance. The inability to consent in advance was significant to a case where someone is unconscious, but it also torpedoes the idea of contracts that guarantee sex.
Again, context is important, and what the SCC wrote is in the context of
this case, i.e. conscious consent. The court ruled that one cannot give
broad consent in advance to sexual acts
that occur when one is unconscious. It did not limit the ability to give consent in advance to specific sexual acts (a sex workers "menu"?)
in general, but did say the law required that consent continue during the act and that in-the-moment consent took precedence over prior consent. Even then it was not a unanimous ruling, as one Justice concluded that consent
could be given in advance of unconsciousness.
You are drawing an inference from this that consent to specific sex acts cannot be given in advance in other situations and therefore torpedoes sex contracts, but the SCC did
not state that. That is your opinion and interpretation, which is fine and the point of this discussion is to benefit from different opinions, but it isn't an open-and-shut legal case by any means.
The point is that if a woman does not consent then it is sexual assault.
If you hire a prostitute and in the middle of the session she demands that you stop, but you don't stop, it becomes rape.
Agreed. I haven't stated otherwise. However, it still doesn't address the issue at hand. There is no "middle of the session" because the session was refused from the start, on the basis of race.
If "service" means a sexual act then yes show can refuse service for any reason at all.
If she also can be hired out to accompany you to a dinner ball, that service probably cannot be refused on the basis of race.
Since you cannot contract for sex in advance legalized prostitution would not mean that sex was guaranteed to paying customers, just not illegal if it happened. Kind of like now.
So you might wind up being able to require the escort to have a conversion in private with you, but you could not require her to perform sex acts against her will.
As I indicated above, the claim that one cannot contract for sex in advance isn't indicated by the SCC case referenced, though perhaps it is elsewhere. However, whether one can or cannot contract for sex in advance isn't central to this discussion.
Leaving that aside, I think this is the likely scenario
if the current laws remain unchanged.
But if prostitution were to "come out into the light" and become a regulated commercial activity, realistically additional laws would be enacted and/or some amendments to existing laws would be in order. I imagine that conflicts between individual rights to security of person and freedom from discrimination would be addressed, if not by Parliament then by the courts.
It will be interesting to see (or more likely,
not see, as the issues are just too thorny for politicians to tackle).