(1) If a person has specialised knowledge based on the person's training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge.
(2) To avoid doubt, and without limiting subsection (1)—
(a) a reference in that subsection to specialised knowledge includes a reference to specialised knowledge of child development and child behaviour (including specialised knowledge of the impact of sexual abuse on children and their development and behaviour during and following the abuse); and
(b) a reference in that subsection to an opinion of a person includes, if the person has specialised knowledge of the kind referred to in paragraph (a), a reference to an opinion relating to either or both of the following—
(i) the development and behaviour of children generally;
(ii) the development and behaviour of children who have been victims of sexual offences, or offences similar to sexual offences.