Unless the interests of justice otherwise require, extrinsic evidence of a statement made by a witness that is inconsistent with any part of his testimony at the hearing shall be excluded unless:
(a) The witness was so examined while testifying as to give him an opportunity to explain or to deny the statement; or
(b) The witness has not been excused from giving further testimony in the action.
(Enacted by Stats. 1965, Ch. 299.)