he is speaking about an area of expertise in which he has no training. He is a Philosphy professor. Similar kooks are the history professor from Temple that "invetigates" UFOs and abductions. Or Bud Hopkins who is an artist that does the same.
All of this means to me that conspiracies are his hobby and as such are not as credible as the opinion of a structural engineer. Now maybe some of the other professors that promote this conspiracy are structural engineers (just not very good ones).