It depends on what your bacon is worth

On a serious note, Yes it is the ph's responsibility to ensure the clients safety, but what do you do when a client acts against your advise. Everytime I get in hunters I spend the first evening with them going over" The Perfect Shot". I advocate that you only shoot shoulder shots, head and neck shots are very difficult if you do not know the anatomy of the animals. I had a client that went against my advice and shot neck shots, he lost two Impalas and eventually got a Bush buck. The moment he saw the animal went down he jumped up and ran to the animal, also against the advice I had given him. If that Bush buck was just stunned and he got up, the hunter would have had a nasty experience, Bush buck can be very dangerous.

When it comes to rifles a ph can also only offer advise, some hunters will just not listen. You got to treat the situation with care, make a compromise as an example that you will follow up after his shot for safety reasons, that is to say if you can. There is very few ph's or outfitters that can afford to lose a client because he disagree on the calibre the client want to use. If a client wants to hunt a buff with a 30-06 I will refuse to guide him, because only a senseless person will try to use a 30-06 on a Buff.

And just to put the record straight, it is not only foreign hunters that stuff up, many local hunters stuff up a lot more sometimes.

The reputation of a ph is also on the line, if you do not go out of your way to save your clients back skin, you might aswell close up your shop.