They have radar, IR, and photo evidence of different events... not the same one.
In fact, in the "big one" posted by the Navy last year, the pilot can be heard communicating with his Hawkeye (I assume) above. Pilot is telling the Hawkeye crew what he is seeing, and the Hawkeye isn't seeing it at all on their systems.
I have no horse in this race. Maybe teenager aliens do flybys of Earth on a dare, once in a while.
But for that to even be a possibility, it would still require the physics of the universe to be COMPLETELY different than anything we have ever conceived of, measured, or observed in the universe and all of our sciences.
I'm opting to stand on the "science" side of this line, for now. I'm willing to have my mind changed, but nothing I have seen so far warrants it. And I was with the Desert Rat on the outskirts of Area 51, worked for NASA, and have friends both in secret military weapons programs and commercial spaceflight companies.