He is right. SCA Heraldry rules on crowns in heraldry must be associated with crown titles obtained throughout the society. If you held a 'crown title' or 'ranking' or 'office' that permitted said crown, it would be permitted in your personal coat of arms/heraldry within SCA and acceptable. Otherwise, the crown is not allowable by their rules. I'm an officer in the Baron of the Bridge (SCA - East Kingdom).