But, as I said, it looks like the early (earliest?) observations were actually of a school plane. Probably some concerned citizen filmed it, and the authorities didn't immediately realize what it was since figuring out the exact place of a light in the sky in a cell phone video isn't that easy.

Could it still be the Russians? Yes, I guess. But if the first observation turns out to have NOT been the Russians, to me that's a bit like how the first crop circles turned out to be a confirmed prank - yeah, technically later ones could still be aliens but given how it started doesn't that seem implausible?

Not to make a comparison otherwise, of course believing in nefarious Russians is a lot more reasonable than believing in mischievous aliens. But I'm trying to make an argument about a causal explanations and a kind of data-generating process, ... not doing too great a job at it I guess.