I am not buying any of this, it just doesn't make sense. Parachinar is way out of Pak-Iran border and there are far better places suitable for the job if Iran is involved which I highly doubt.
One must consider the possibility of foreign involvement, i.e. misinformation to create troubles between Pakistan and Iran. CPEC is happening, internal security is improving and our economy is back on track. The adversary is desperate to utilise all the options to create problems and media is easily bought or manipulated. A new wave of sectarian violence and diplomatic standoff between Pakistan and Iran is exactly what they want.
Nisar Chowdhry is a good man. If the rumors were true, he would have raised his voice. He was the who openly questioned Iran's role in a recent drone attack.