Yours is a poor analogy (they can't even sell gum to the public without a retail license, etc., etc.). Just work with the scenario I responded to.So using your line of reasoning, if an MP sold each customer a pack of gum for $150 prior to the session and received sexual services after then it would confirm to the law. This is because "it shouldn't automatically mean that he paid for 'everything being provided'.". You are right in that the crown can't just assume that everyone who enters a MP is guilty of purchasing a sexual service, but let's say during a bylaw checkup they catch you getting jerked off by an MPA - What reasonable conclusion would they be able to draw? Your defense is entirely based on plausible deniability. From the officers standpoint, if they wanted to enforce the law, may not sound that plausible at all.
I visit a MP. Pay for the room and the body rub first (as is the practice with certain BRPs). They are not selling sex. I have no more money in my pocket. I score a HJ or BJ (maybe for being a repeat customer or it's a loss leader, but nobody knows for sure, nor is anything admitted except perhaps, "I like him"). There's no evidence that she got paid for an extra, or that I will pay her for an extra. C'est tout.
So what is the evidence, based SOLELY on a momentary visual that is beyond a reasonable doubt, that I paid for that sex or communicated for it, if all they did was open the door and see us in a brief intimate moment? Is there anything to corroborate the purchase of a sexual service?