So what do you think the F-18 was tracking with its FLIR that flew like no known aircraft off the coast of CA?
It’s documented evidence.
Probably a smart missile performing test extremes no human could physically endure. Maybe it even has a reverse thrust ability to make the smart anti-missile missile unable to stay with it.
It was a secret weapon with a vectored thrust engine like the Harrier, which has been observed turning right angle corners. 1950s and 60s technology with some fancy new propulsion upgrades.