18.—(1) Subject to subsections (2) and (3), for the purpose of the performance of every function under this Part the Board shall presume that the claimant and the respondent or respondents are each of full capacity.

(2) If—

(a) rules under section 46 require an application under section 11 to include a statement that the claimant is of full age, or

(b) rules under that section require the Board, before it deals with a claimant or a respondent under this Part, to seek confirmation from the claimant or the respondent that he or she is of full age,

then subsection (1), in so far as it relates to a person’s being of full age, shall not apply unless and until that requirement of those rules is complied with or that confirmation is given by the claimant or the respondent.

(3) Subject to subsection (4), if, during the course of the performance by the Board of its functions under this Part, a medical opinion in writing is furnished to the Board to the effect that the claimant or a respondent is not of sound mind then the presumption in subsection (1) shall be regarded as rebutted and the Board shall, as appropriate—

F22[(a) not arrange for the making of an assessment of, or the carrying out of mediation in relation to, the relevant claim concerned, or

(b) if any step in the making of that assessment or carrying out of that mediation, or consequent on the making of that assessment or carrying out of that mediation, has already been taken, cause no further step to be taken in the making of that assessment or carrying out of that mediation or consequent on its making or carrying out,]

unless, in the case of such an opinion that has been furnished in respect of one or more than one of 2 or more respondents, no such opinion has been furnished in respect of the other or others or the claimant.

(4) Nothing in subsection (1) or paragraph (a) or (b) of subsection (3) applies if—

(a) in the case of a claimant, a next friend or a committee of the claimant is acting on his or her behalf, and

(b) in the case of a respondent, a guardian or a committee of the respondent is acting on his or her behalf.

(5) No action or proceeding shall lie against the Board or any of its members or employees in respect of anything which the Board, the member or the employee could have lawfully done or omitted to do had the circumstances presumed by virtue of subsection (1) to pertain pertained in fact.

(6) If such an opinion as is referred to in subsection (3) is furnished in respect of one or more than one, but not all, of 2 or more respondents and subsection (4) does not apply then the Board shall record in writing the fact of its having received that opinion and no assessment made under this Part in relation to the relevant claim shall bind the respondent or respondents to whom the opinion relates.