But would we have been all that shocked? We are not talking about a child here, but about a young woman. Buying sex from prostitutes is not something to be approved of, but it happens all the time - always has done and always will, while men want it and it is available. If he had the money and was free to spend it as he wished - then if he DID do so, that was his choice, that was his business.
That the man was about 40 and the girl 17 - well, presumably attractive and fairly young prostitutes are more popular than older ones, and can command larger fees, and in this country, sex at 17 is legal.
Her previous history is not really relevant if the man she entertained was ignorant of it, and did not treat her badly himself. Sex at 17 in a luxurious setting with an appreciative and not repulsive client with the prospect of a generous cash present is not necessarily an obnoxious way of spending a weekend. I don't think I would do it myself, but plenty of girls would at least consider it.
What I don't believe IS legal is what used to be called "living on immoral earnings" or pimping - managing a stable of girls and renting them out. If someone is taken to a house party to entertain a man, and given several thousands of pounds for it by her friend Whatsischops, then Whatsischops must have got that money from somewhere, or more likely a lot more than he gave her, keeping some back for himself.