There's an account here. Under U.S. law, none of this would be libel, but Canadian law is far less forgiving of defamation than American law, though I'm skeptical the statements in question are defamatory even under Canadian law, though "misogynist" may be arguable (if it were false that he were a misogynist, but it's probably true). Even if he secured a libel judgment against Professor Manne in Canada, it would not be enforceable in the United States against her.
UPDATE: A couple of readers point out to me that on social media the Vancouver miscreant Jonathan Ichikawa made the following remarkable statement: “The amazing part is that people like Peterson and Leiter have valuing free speech as a pretty central part of their brand. How one can conceptualise oneself as a free speech hero while employing such blatantly bullying tactics to silence, I'll never understand.” Free speech doesn’t include the freedom to libel others (or the freedom to engage in other unlawful speech). Recall that even Ichikawa’s own lawyer wouldn’t defend his and Carrie Jenkins's false factual statements about me as “true.” As I noted at the time: "Jenkins and Ichikawa, through their lawyer...in rejecting the [proposed] settlement...did not assert that the challenged claims...were true (or 'substantially true,' the relevant language in this context), but only that they constitute 'lawful expression under the law of Canada and the First Amendment of the U.S. Constitution.'" And this choice of language was revealing, since as their own lawyer has written in a treatise on Canadian defamation law, "A decision to plead justification [i.e., that the statements are true] should not be made lightly. An unsuccessful plea of justification may be taken into account by the court when assessing damages....[A] failed plea of truth may aggravate the plaintiff's damages or underpin an award of exemplary damages. It may also lead to a more substantial award of costs against a defendant." Thus, their legal response was an effective admission that they really couldn't defend their statements as true or even "substantially" true. In any case, Ichikawa and Jenkins have a track record of trying to punish those engaged in lawful expression that they find offensive (they are notorious at their university on this score, I've since learned). So there's no mystery at all about my position on free speech, unless you’re a dishonest weasel like Ichikawa. I increasingly regret not suing those miscreants, but at the time it didn’t seem like the damages would be sufficient to justify the hassle.