As I recall everyone involved were surprised by #1 and truly very frightened by #2 and #3. All 3 incidents were outside a frame of reference and were not categorized by anything but surprise.

The only thing these incidents have in common is that they have never happened since. A true one off.

The most terrifying was the sound which translated into being unable and unwilling to respond in any meaningful way. (scared stiff) I always heard reports that something like a ufo is silent. So in conclusion, I dunno.