This series was based on Project Blue Book, and one of the former officers assigned to Blue Book was actually a technical adviser to the show.
The problem, of course, is that today, we know that Blue Book was an attempt at Public Relations by the USAF to show that they had a handle on this UFO thing when they really didn't, and that they frequently used the most ludicrous explanations for sightings they could think of. Usually, an officer who was assigned to Blue Book was someone who was at a career dead end, and the Air Force was happy to get out of the whole thing in 1969.
The problem with Jack Webb's concept is that he tried to treat it like one of his cop shows, but still create a little action. So you'd have this elaborate special effects sequence setting up the story, followed by some "prosaic explanation" (as famous UFO Debunker Phil Klass used to say) as to what they actually saw. OH, that was swamp gas? Really?
To be absolutely fair, they were right. 95% of UFO sightings can be explained as something that was misidentified by people. Still, that didn't make for very good drama. The Air Force even cooperated in this series, hoping it would be good PR, but it was anything but.
