What is the test for a "matching report" in a medical malpractice case?

Furthermore, "the fact that a particular medical specialist examined the plaintiff does not satisfy the required relevance [page622] threshold without some additional evidence that the proposed examination is relevant to a medical issue in the case": Lavereau, supra, at para. 17. "In any case, the case law has established that a 'matching report' is not needed in order to level the playing field": MacDonald v. Rai, [2005] O.J. No. 2556, 140 A.C.W.S. (3d) 45 (S.C.J.), at para. 6. In other words the mere fact that the plaintiff chooses to retain a particular specialist does not automatically give a right to the defendant to have a report by the same specialist without evidence as to the nature and relevance of the proposed examination. Put another way, there is no automatic "tit for tat".