In reply to Max_01:
There's an echo in here here here..
You don't 'need' a certificate to take others anywhere.
If a member of a party gets injured then the lack of a qualification of any kind won't have caused the injury, will it?
In a court what will happen will be that the case will hinge around whether the leader was guilty of negligence - that can happen to people both with and without qualifications. The question might well be asked ' well Mr Max_01, just how did you know that you were competent to undertake this particular expedition; do you have any evidence to suggest that you were, in fact competent...?' You don't get done just because you haven't got a piece of paper (because there is no law that says you need one!) you get done becasue you didn't look after folks like you should.
It will also hinge on the nature of the group. The level of 'duty of care' expected of someone who is taking money to lead commercially is way different to the level required of a member of a party of mates going for 'a stroll'.
Not convinced that the 'holder of the map' is automatically the leader