I'm surprised by this story - isn't it polite to talk to the SP before you use them as a reference? That's the standard I follow in hobby and in business.
Sure it is but that doesn't mean it happens. I ask for that but some newer hobbyist don't know. He learned to ask the SP before hand for future but now he will just use me as reference and won't have that problem. And I personally don't care if they check with me first. Not at all.
Point is a mistake from a client who didn't know it is respectful to ask first but not law should not out weigh the attempt at calling "dibs" on a client because you don't want him spending money on another escort. One is a mistake the other is unprofessional. In my opinion anyway.

