Quote Originally Posted by O'Callaghan View Post
Heralds were originally blowers of trumpets and recorders of battle honours, for which they had to be able to recognise the combatants by their livery. From that they grew to be authorities and eventually arbiters of what we now call heraldry. However, it has come to a sad point if a herald can tell you whether you exist....

If there is even one left then there is always someone who could claim the title of chief, and a herald would be presumptious to say anything more than whether they are entitled to a particular coat of arms.
It is not the authority of the herald's office itself (or Lord Lyon, in the case of Scotland) that determines the status of a clan but that of the sovereign, the fount of honor (or honour, as they call it there), which is the Crown in the UK and the Republic in Ireland. In the UK the Crown has delegated this responsibility to Lord Lyon as to the chiefships and existence of Scots clans. If you disagree with this way of doing things, I suggest you take it up with her.