If an authorised person does something that, apart from this section, would be an offence, the authorised person is not criminally responsible for the offence if—
(a) the thing is done in the course of acquiring or using an assumed identity under an authority; and
(b) the thing is done—(i) for an authorised identity officer—in the course of duty; or(ii) for an authorised civilian—in accordance with the directions of the authorised civilian’s supervisor; and
(c) doing the thing would not be an offence if the assumed identity were the authorised person’s real identity.