[macspoofing]

> I think it's more reasonable to assume it belongs to the US Government, which would perfectly explain why they don't really view it as a threat.

You can't just conclude this. It could be other things like a sensor glitches. Or sensor confusion (e.g. tracking a bird heading in the opposite direction, or out of focus commercial plane). Or it could be something else entirely you aren't creative enough to think of.

The default position is "I don't know", not "Aliens" or "US Government" or "Unicorns"