You ARE aware that this was during a phase when all PAF aircraft were flying back into Pakistan, and even a pursuing aircraft when shot down fell into Azad Kashmir territory.
One, it could not be fired from any other aircraft in the PAF inventory; two, that was precisely the point, to remind everyone that F16s were involved.
It is easy to forget that the use of F16s in such a situation creates a difficulty for the US. Showing that these aircraft were involved was a very purposeful action, beyond the scope of showing that a plane was down.
Perhaps. Perhaps not. Only the PAF can say, and we already know that there are things that they will and will not say.