1. It was an air launched version of Brahmos.
2. It was a simulated exercise by IAF, with Rafiqui AFB as a potential target (Mian Channu is in line with Rafiqui by 20 seconds at Mach 3, it was used to simply simulate Rafiqui as its target).
3. IAF was conducting what is considered an ORI, an exercise whereby the base needs to conduct a war-time mission, with a live weapon, albeit the final trigger is pressed in a simulated scenario. In this case, the aircraft never went into sim mode. IAF has axed 3 officers so far, more on the line.
4. The lack of proficiency of IAF targeting staff delivers, yet again. The pilot's career is gone, but had this strike connected to say even a school or hospital, a retaliatory strike was 100% guaranteed.