That's not why Mac doesn't let the kid on the air. It's because he was trying to hijack the issue of a fellow student (that he didn't even know) being humiliated into suicide so that he could come out to his parents publicly rather than in person.
Mary does everything a good rape victim is supposed to: she goes to campus/local police and gets tested with a rape kit. The result being, of course, that absolutely nothing is done to bring her assailants to justice. If she wants to take her own story to a public forum (and, presumably, the accused has no issues with appearing as well), it's not up to Don to tell her it's not in her best interests.
