That's what I want to know.
It is fairly easy to ascertain that it was from the air, and locals have (or did) become pretty good at it according to someone I knew (he was from Parachinar).
He said that when they heard the sound of a jet they knew it wasn't a drone, and that jets didn't fire at them so they assumed them to be Pakistani. With a drone it's just you are sitting peacefully and then bam, out of nowhere.
Of course no way for the people on the ground to conclusively say so, unless they saw a missile streak from the air.