P. Aarne Vesilind's Commentary on "Confidentiality Concerns"
Information does not have to be shared. If there is no good reason for sharing information, and if sharing it would in fact cause damage, then one is obligated to keep the information to himself or herself.
Not volunteering information is not lying, and it is not deception. Suppose Schmidt had asked Bernhard whether Maxwell had said anything about her performance on the exam. If Bernhard had said (untruthfully) that Maxwell had not, he would have been lying. Saying nothing is not deception, which presumes some expected sharing of information. Suppose Schmidt knew that Bernhard had a meeting with his adviser, Maxwell, and asked Bernhard afterward if Maxwell had said anything interesting. Maxwell's comments on Schmidt's performance are obviously interesting to Schmidt, and a negative response from Bernhard would have been deceptive. Schmidt should not have been expected to ask specifically whether Maxwell had said anything about her (Schmidt's) exam.
But none of that occurred. Bernhard possessed information that would cause Schmidt great anxiety if he volunteered it to her. Why, then, should he tell her? For what good purpose? What he should have done is to keep quiet until the test results were in and the situation had stabilized. At that point, he had a difficult decision to make: whether to tell someone such as Campbell (Schmidt's adviser) or the departmental chair. Because Bernhard had no reason to tell Campbell, it seems that the logical alternative for him would be to tell the departmental chair and hope that Maxwell would be cautioned against sharing confidential information with students.
I am aware of the philosophical argument that all information is to be shared and that this is the only way we can be assured of getting along with each other. We might argue that Bernhard's silence might cause him personal anxiety and might change his relationship with Schmidt, causing her to doubt his friendship. But these are minor concerns compared to the life-long relationship Bernhard would expect to have with Schmidt. There is nothing wrong with occasionally declining to volunteer information.