(1) This section only applies to a civil proceeding in connection with which 2 or more parties have, before the start of the proceeding, jointly retained a lawyer in relation to the same matter.
(2) This division does not prevent 1 of those parties from presenting evidence of—
(a) a communication made by any 1 of them to the lawyer; or
(b) the contents of a confidential document prepared by or at the direction or request of any 1 of them;
in connection with that matter.