From a poster on another website. He sums it up!
[Limiting their study to 2004 or later, and then offering the excuse that they haven’t enough data to reach any conclusions is a ridiculous and evasive stance. What of all the reports, known to have been collected by the military between 1943 and 2003?! This pose of deferring a conclusion indefinitely because further study is needed will not fly.]
And another!
[It seems to strongly suggest aliens but the writers of the report seem to have been told not to use that word.]
Just a WAG without having read the report.
Limiting the study to 2004 or later. Probably want to use data from sensors that can give them reliable worthwhile information. Early radar and other surveillance equipment probably wasn’t sensitive enough and also probably no longer available to make comparisons.
Most eyewitness reports are worthless from a technical point of view.
And you are probably dealing with professional scientists and technicians who are reluctant (to say the least) to say anything that might get them depicted as a nut or otherwise threaten their credibility.
And, lastly, without actually being able to lay hands on one of these gizmos, they really don’t know exactly what it is.
Just my two cents.