It seems to me like the PH may have knowingly violated the law, but there has been no evidence to show that the American hunter knew his guide was setting up an illegal hunt.
Is an American angler breaking the law if he steps onto a guide's boat and the guide takes him to a spot that is in provate water and they are trespassing? I don't think so. There is a legal concept called mens rae.
Another example in American law would be a guide taking a customer to hunt waterfowl over a baited field. Should the customer be found guilty if the guide knew the field was baited but the customer was simply tricked by the guide?
https://en.wikipedia.org/wiki/Mens_rea
Customers trust their guides to keep them in compliance with the local laws.