I wonder how much of the second stage flight is autonomous and if they need to continually need to give it a go to continue, or if it aborts automatically after some time of lost telemetry. But maybe it already exploded anyways.
But interesting that telemetry showed the failures starting a few seconds before loss of telemetry, the videos posted here show a massive explosion later on. So something was going wrong for some time before, and the explosion was only a consequence of that.
Or it was the FTS reacting to the engine failures.
In the Space Shuttle, given that it was human rated, the "Range Safety" system was completely manual. It was controlled by a pair of individuals and they manually made the call to send the ARM/FIRE sequence to the range safety detonators.
The AFTS has independent, hardened, validated inertial measurement systems.