Read this article, confirms that there was 50 second gap from firing the R-73 to Wing Commander being shot down, Other IAF aircraft Alpha2 or a SU-30 should have fired R-77's from locking on to the Mig 21 Bison. The wasting of R-77 may have been against IAF ethos, I hope the IAF makes changes.
And I hope the PAF is given its medicine with SU-30 firing at Mach 2 missiles at slower flying F-16's.
The Su-30MKI did a good job avoiding Amraam's shot at them by aircraft coming in high and fast- this was the best case scenario in F-16 Vs SU30MKI and still flopped- IAF aircraft at subsonic CAP just checking to see what PAF aircraft are upto when the launch their missiles at Max speed and altitude.
The issue is situational awareness. What you are suggesting is in the hindsight. When the F16 got hit, would all the pilots including the Su30 know what just happened? Nope. So within 50 sec, expecting pilots & GC( in multiple sectors) to clearly understand the situation and apply counter measure is bit too much.
My theory is that the 50 sec gap indicates, PAF had no intention of shooting down the Mig21 as it was flying towards them. It was only after WC Abhi fired one on to the Musharaff of that F16 that they forced to retaliate. Otherwise WC Abhi would have got hit ingressing across LC, not while coming back.
PAF was gunning for glory... i.e. Su30.