13Circumstances in which conduct takes place without free agreement
(1)For the purposes of section 12, but without prejudice to the generality of that section, free agreement to conduct is absent in the circumstances set out in subsection (2).
(2)Those circumstances are—
(a)where the conduct occurs at a time when B is incapable because of the effect of alcohol or any other substance of consenting to it,
(b)where B agrees or submits to the conduct because of violence used against B or any other person, or because of threats of violence made against B or any other person,
(c)where B agrees or submits to the conduct because B is unlawfully detained by A,
(d)where B agrees or submits to the conduct because B is mistaken, as a result of deception by A, as to the nature or purpose of the conduct,
(e)where B agrees or submits to the conduct because A induces B to agree or submit to the conduct by impersonating a person known personally to B, or
(f)where the only expression or indication of agreement to the conduct is from a person other than B.
(3)References in this section to A and to B are to be construed in accordance with sections 1 to 9.