The above video was presented by Knuth in February:
In the presentation he shows two objects fly over, the first is bright, and glare-shaped and he says it's a passenger jet showing up as warmer than -64°F
The next thing looks like a triangle of three dots.
If you go by the scale, it's about -55°
However I did some backyard experiments with my FLIR, and found that small objects against the sky show up as much colder than they are. unfortunately it's overcast here. But using this scene:
In about 75° weather, I measured the temperature of the black rubber junction above the bulb:
45°, and measuring the rubber up close, it was actually more like 80°
I'll try this again against a clear blue sky, and maybe a night sky. But I think it already shows that temperature measurements of small objects against the sky are not reliable.