Is it the U.S. government?
The tactic of using strange sightings of potentially classified aircraft as a psychological operation wasn't unfamiliar to U.S. military officials.
It became amongst the very first fatalities of the U.S. Air Force when the plane crashed and they were both killed, and the UFO material vanished with them.
Not only were America's adversaries exploring experimental aircraft, but the U.S. was secretly developing advanced spy planes and stealth fighters, such as the SR-71 Blackbird, and later the F-117 Nighthawk, through black projects at Lockheed Martin's Skunk Works division.