In Herbert v. Lankershim (1937) 9 Cal.2d 409, the court recognized the exception which here is applicable. There the court, after holding that a minor change in the proffered instruction (the words "a presumption of undue influence" should have been substituted for "presumption of fraud") should have been made, states: "We think this is the rule approved by statute and judicial decision where fundamentals are involved, there being no attempt on the part of the author to mislead the court or jury by resorting to equivocally or ingeniously phrased requests, . . ." (Id. at pp. 482-483.)