That’s not just a matter of pressing the trigger, is it? You have to align the fuselage to the target first?
Those rounds go where the plane is aimed
I really don’t have any information that could shed light on this incident, as I am not conversant with the F-16 fire control system.
HST, one generally does not aim one’s gun at something one does not want to shoot at.
Probably will come down to a pilot error incident.