A friend went to an Asian Massage Parlor a few days back. He has a few questions.

Last week my friend went to an Asian massage parlor. He is concerned since he used his credit card to make the payment. The questions that interest him are as follows:
1. What is the probability of police targeting previous clients in case of a bust?
2. Is he right to be concerned knowing that he paid a lot of tip, nearly one hundred and fifty U.S dollars.
3. Besides the record of the credit card transaction, what would actually be required in-court to prove him guilty of solicitation? The only things that come to my mind are video or photo evidence or testimony from the masseuse. How much probability there is that she would accept a plea deal and testify against him?
Thank you and I will appreciate any answers you could give him