23Where in accordance with the regulations an industrial tribunal determines in the same proceedings—
(a)a question referred to it under Part I of the [1965 c. 62.] Redundancy Payments Act 1965, and
(b)a complaint presented under paragraph 17 above,
section 9(2)(b) of that Act (whereby a dismissal is to be presumed, unless the contrary is proved, to have been by reason of redundancy) shall not have effect for the purposes of the proceedings in so far as they relate to the complaint under paragraph 17 above.