They probably believed the 150km was fake and the real range was 100km.
Ultimately, all this attention on the perceived-real range of the PL-15 is just smoke and mirrors.
So what if it was 100km? And if the PAF crossed the border to get within launch range, the excuse will be "we (IAF) were not going to cross the Border so we expected PAF to be gentlemanly and also stay on their side"?
And so what if it is really 200km? It affords the PAF the luxury of launching at a distance out of harms way BUT ... The reality of it is that, whether 100km or 150km or 200km, the final few 10kms are the same.
- The IAF did not detect the incoming Fox Three.
- If they did, the IAF did not manage to defeat the incoming PL-15s whether by ECM or Countermeasures.
- If they actually even saw the incoming missiles, there was enough smash that the planes shot down couldn't even lose the missiles with evasive maneuvers.
This says a lot as quoted MAX range mean nothing if your missile does not have enough energy at those range to prosecute maneuverable targets. Depending on where we are on the above list of IAF not being able to detect/see/evade the incoming PL-15s, it either reinforces their incompetence or if they still insists they are not incompetent, then the kinematics of the PL-15 must really be top of their class.
Being able to reach out and down a modern, fighter aircraft at ranges >100km is big boys league stuff. Doing it in a combat environment is icing on the cake as it cuts out all the bullshit about benign test/exercise parameters.