...has made a serious error of judgement and must apologise.
In apparently giving support to a group that supports mutilation of children, he has blundered badly.
Making a mistake is easy - we all do it. The only thing to do is admit it, take appropriate action - in this case issuing a formal apology - and learn from the experience. The Prince will learn to recognise the need for discernment and wisdom when confronted by new trends and lobby groups.Meanwhile the rule "first do no harm" is a generally useful one.