While the show was interesting, my husband and I found it to be a lot of Monday morning quarterbacking....IF the structure had different fireproofing or IF the structure hadn't used dry wall...basically just blaming decisions from 30 years as being cheap and stupid (you know, back when we didn't have the technology to use computer models....)
and, being PBS, IF anybody had flat out said, "well, the towers fell because insane, militant idiots crashed huge jetliners into them" it was edited out.