Even scientist are humans and have eyes, is the same bias, you don't need special equipment/training to see something as big as a football field moving in the sky blocking stars light without making a sound and still think that is a military craft.
Also having thousands confirm the event rules out a hoax, on top of that the former governor who was also a trained pilot could easily identify flares or other military plane. You need to look at all the evidence and details.
To have a piece of alien technology you can only have it if you receive it, you or me will surely not be that special to receive it and if world leaders will have the privilege you might never know.
Also it's enough proof to hover that big craft in mid day over a big city but for whatever reasons they still give us a chance to doubt, I suspect that the reason is to avoid panic as a big percentage of world population is still religious and not ready yet but they still give us a sign that we are not alone.
There are 4 videos shot from the event on youtube that you can watch, also high definition cameras still don't have very good optics to focus on moving objects at high altitude, a better sensor alone will not help much with the video quality especially in the night.
Also these kinds of events are very rare so there too many things, like good camera with good lenses, tripod, being in the right spot, last long enough etc to be in place to get that clear hd video.