drankin

Opening 1 NT with a singleton by agreement has been deemed a convention by the ACBL and that convention is barred at ACBL events. So if the club is following the GCC and that agreement exists, it is illegal and subject to PP. (Barred unless it is forcing, as in the Romex system.)

Since East has not yet called over 2H, the director has a duty to explain to West that he may change his call if it was based on the incorrect explanation. Since E/W made no further bids, this may not seem important, but East is entitled to know that West would still pass a natural 2D bid, before he has to consider his action over North's 2H bid. No doubt this is why the director is to be called.