If playing in an SBU event with a non-playing Director please follow Law 9B(a) "The director should be summoned at once when attention is drawn to an irregularity"
No matter how well you think you know the Laws, they are generally more complex than you might think – a ruling that applies in one situation need not also apply to a similar but slightly different one.
Home-made rulings may be half-baked!
Insisting that you know the Laws and enforcing them without consulting the Law Book or a Director may be construed as Bullying, particularly against inexperienced opponents.
In the Club, with a playing Director who may not yet have played the board, it is less straightforward. You probably need a number of members capable of giving a ruling, any one of whom can act as the Director's deputy.
Be sure always to consult the Laws – everybody has a responsibility to familiarise themselves with them and to follow them.