One simple reason to not go into depth on the evidence is it would reveal the capabilities of radars and similar sensors. Likewise, if they know one of these w

One simple reason to not go into depth on the evidence is it would reveal the capabilities of radars and similar sensors. Likewise, if they know one of these was say a drone test by a contractor from a grey/black program they're obviously not going to disclose that. So there's a bunch of banal reasons security could apply here.