Again, my legal perspective would say it is the "best practice" idea of the person who works for/sits on the licensing board at this point in time who may have thought it unusual for a client to be asking this question. If someone else had answered the email or other people were sitting on the board, the answer would be different. The reason why anyone can say "best practice" is because there is much disagreement among the field-- otherwise this best practice would be codified in the actual ethics rules or statute (if he's talking about the professional rules as incorporated into the state licensing requirements). Such a large landscape between the actual law of "no sexual relationships" and what is being interpreted as "best practices." And sometimes best practices mean what you should do to avoid being sued, and perhaps that's another of his motivations. I guess if I were advising a professional I would encourage him to follow the best practices of his profession, and I'd want him to err on the side of safety. For sure I feel like avoiding litigation or CYA is often a powerful motivator for people, professional or not.