My sense is that Markham LE are always being assholic on Found-In charges. Could it not be argued, somewhat jokingly though, that the guy taking a whiz has a valid excuse for being in the establishment?
I like your point about the guy just sitting in reception being charged as a "Found-In". I don't think enough people realize that "Found-In" charges are what people face when they are caught in an MP. The definition of "Found-In" is anyone who does not have a reasonable excuse for being in the premises at the time it is being raided as a "common bawdy house."
Also, some people have raised a question about a license. Though it appears that the MP in question did not have a valid Body Rub, Holistic or Municipal License, even if it did, the license does not protect an establishment from having "Found-In" charges laid against the occupants. I've said it before and I'll say it again, a license on an MP- no matter who issues it - does not give the MP's occupants and customers immunity from the Criminal Code of Canada. It's like a doctor who commits a criminal act or a civil tort in his practice and then stands up and says "I'm immune from the Criminal Code and being sued because I have a license to practice medicine."
According to the letter of the law, if you are found in a licensed establishment - anywhere in Canada - at the time it is being raided as a "Common Bawdy House" you could be charged as a "Found-In". In practice, LE in certain areas may not care as much about licensed establishments, and they may not lay these kinds of charges at licensed places - but that is their discretion. The letter of the law (and the risk we run in visiting any MP) allows for charges even if there is a license.