Delivery to a person's order of shares or debentures in fulfilment of a contract for the purchase of them by him or in satisfaction of a right of his call for their delivery, or failure to deliver shares or debentures in accordance with the terms of such a contract or on which such a right falls to be satisfied, is deemed to constitute an event in consequence of the occurrence of which he ceases to be interested in them, and so is the lapse of a person's right to call for delivery of shares or debentures.