In either scenario I am the guy in the other seat and the Captain is getting ready to kill me and everyone else aboard. I say something.
As for the plane. Suddenly blinking off of the radar. No distress call, auto or manual. There was a sudden catastrophic event. Mechanical? A bomb? Waits to be seen. And it doesn’t take a bomb to find little bits of a plane here and there after an accident. Math and gravity solve that for us.