Notwithstanding Conditions 6 and 7, if the Auctioneer receives notice in writing from the Buyer WITHIN 7 DAYS OF THE SALE that in his opinion a lot is a forgery (as defined in Condition 12) and on giving such notification the lot in question is returned to the Auctioneer at his working premises in the same condition as when bought, then if on considering such evidence as the Buyer supplies to prove his assertion, the Auctioneer decides that the lot is a forgery the sale of the lot will be rescinded and the purchase price repaid to the Buyer.