[yeeeloit]

We, the general public, simply do not have enough information at this point to judge this man's testimony, or the evidence that he provided.

[dmix]

We do have a long, colourful history of "reputable" people (aka "I worked at the gov" or "I have a Harvard degree") making such claims (and not just about aliens but various hidden US gov tech) and combined with that we can do basic reasoning about how the US gov operates, the extreme difficulties/limitations of interstellar travel, how information can turn into a "telephone game", the other 1.25 million people with the same top secret clearance, the claim basically amounting to hearsay with no direct witnesses or participants in the program, etc.

I'm personally not waiting at the edge of my seat.

[rbanffy]

We have enough knowledge of physics to say these are extraordinary claims that require some extraordinary evidence.