Agreed. I'm of the stance that I only downvote trolling or absurd claims without any form of supporting details. Otherwise, I prefer to take the route of elaborating/correcting/questioning/etc even if I'm not an expert on the subject because then it at least fosters a discussion and sets up a path for shorter corrective comments from those that don't have the time/motivation/energy to respond in more detail.
I rarely make the mistake of speaking with certainty about something I'm not sure of, so I guess the down votes were warranted. But I am surprised that a tenured professor at an elite university would be so wrong in his area of expertise. A cursory googling shows that there has been some decent research on muscle relaxation as a mechanism to reduce anxiety, though I concede that Diazepam probably has higher order effects that compound is efficacy:
