Presumably in example sentence
It is 1) unrealistic that Irene Dunn, missing at sea for seven years, should reappear on the very day that husband, Cary Grant, has succeeded in having her declared dead and then, moments later, remarried in the same courtroom and 2) that Grant's mother would not have attended the wedding; presumably the writers needed Dunne's mother-in-law to be in when Dunne (who naturally would not have known about the new wedding so would have no reason to attend and try to stop it) resurfaced though a little thought could have solved this.