(1) If a single expert witness has been appointed to prepare a report or give evidence in relation to an issue, a party must not tender a report or adduce evidence from another expert witness on the same issue without the court's permission.
(2) The court may allow a party to tender a report or adduce evidence from another expert witness on the same issue if it is satisfied that:
(a) there is a substantial body of opinion contrary to any opinion given by the single expert witness and the contrary opinion is or may be necessary for determining the issue; or
(b) another expert witness knows of matters, not known to the single expert witness, that may be necessary for determining the issue; or
(c) there is another special reason for adducing evidence from another expert witness.