Boucher v. Wal-Mart Canada Corp., 2014 ONCA 419d
 The tort of intentional infliction of mental suffering has three elements. The plaintiff must prove:
· The defendant's conduct was flagrant and outrageous;
· The defendant's conduct was calculated to harm the plaintiff;
· The defendant's conduct caused the plaintiff to suffer a visible and provable illness.
See Prinzo v. Baycrest Centre for Geriatric Care (2002), 60 O.R. (3d) 474 (C.A.).
 The trial judge instructed the jury several times on the three elements of the tort. Pinnock submits that the trial judge misstated the second element. She told the jury:
In determining whether the conduct was calculated to produce harm, you must be satisfied that Mr. Pinnock either intended to produce the consequences or alternatively, ought to have known that the consequences were substantially certain to occur. Has it been established that Mr. Pinnock intended to cause mental suffering on the part of Ms. Boucher, or engaged in conduct that was substantially certain to cause such suffering? [Emphasis added.]
 The alternative, that Pinnock could be liable if he "ought to have known" the consequences were substantially certain to occur, is wrong, he contends, because it imports an objective test into the tort. I am inclined to agree that the trial judge misstated the second element. The test is purely subjective as Weiler J.A. said inPrinzo, at para. 61:
[F]or the conduct to be calculated to produce harm, either the actor must desire to produce the consequences that follow, or the consequences must be known by the actor to be substantially certain to follow.
See also Piresferreira v. Ayotte, 2010 ONCA 384, 319 D.L.R. (4th) 665, leave to appeal to S.C.C. refused,  S.C.C.A. No. 283, at para. 75.
 The plaintiff cannot establish intentional infliction of mental suffering by showing only that the defendant ought to have known that harm would occur. The defendant must have intended to produce the kind of harm that occurred or have known that it was almost certain to occur: see Piresferreira, at para. 78.