What is the legal test for inference that confidential information was imparted?

In Martin v. Gray, Sopinka, J. said the following about the inference that confidential information was imparted, at p 268: ... the court should infer that confidential information was imparted unless the solicitor satisfies the court that no information was imparted which could be relevant. This will be a difficult burden to discharge. Not only must the court’s degree of satisfaction be such that it would withstand the scrutiny of the reasonably informed member of the public that no such information passed, but the burden must be discharged without revealing the specifics of the privileged communication. None the less, I am of the opinion that the door should not be shut completely on a solicitor who wishes to discharge this heavy burden.