What's with all these conspiracy theories? What happened was very simple.
Mig21 shoots down F16
Mig21 then gets shot down
Pakistan claims to also shoot down Su30 so as not to lose face, expecting clear evidence of downed f16 to be revealed.
Lucky for Pakistan, they could deny their f16 loss.
They then withdraw anything about shooting Su30 as they have no need to save face anymore.
Being very conservation here is what likely happened:
F16 fired at SU-30 as it might have threatened the Strike Package. Su-30 did evasive maneuver & escaped with non-fatal damage. Pilot was able to recover the aircraft to an airbase.
This explains:
i) Initial News on Indian Channel that Su-30 was shot down.
ii) Second Su-30 leaving the area afterwards.
ii) PAF claim of Su-30 being hit based on radar data, data from F-16 computer, intercepted radio communication. Remember PAF memorial mentioned "Avenger" call sign before India acknowledged this info publicly.
iii) The piece of AMRAAM which show sign of warhead triggering(deformed, ragged edges & folded outwards).
iv) IAF patch celebrating AMRAAM Dodger; possibly celebrating pilot's flying to escape with non-fatal damage & being able to recover the aircraft.
v) Lack of Su-30 wreckage.
Mig-21 scrambled, unintentionally crossed LOC due to radio jamming. Was shot down by another F-16.
Lack of Evidence to support even Mig-21 firing anything let alone F-16 kill:
1) No wreckage
2) OSINT and later PAF showed all 4 missiles either intact or still connected to airframe at time of crash.
3) Foreign Policy article confirming no F-16 shot.
4) On one hand India themselves claim that Abhinandan could hear his controller because of communication jamming, but under same conditions he was able to relay back to his controller that he shot down an F-16?
5) Indian Media reported that Su-30s radars could not get lock on to F-16(again possibly due to jamming by PAF), but under same condition relies on a blip going off radar scope as confirmation of kill. What if that blip wasn't a real plane in 1st place; that's how jamming works i.e you saturate radar with false returns. What if it was but then flew behind a mountain or jamming caused the radar processor to filter out the clutter altogether?
ISPR in fog of war made mistake of double counting abhinandan as 2 pilots. IAF waited for situation to clear up. Knew Mig-21 with pilot is on Pakistani side and that Su-30 wreckage/damage isn't in public domain so confirmed one loss and then added a F-16 shot down story to save face.