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.
The flight control loops are strongly latched. They are constantly checking the state of discretes, control surfaces, and intended guidance. If any critical parameter gets out of range for a period of time or if any group of standard parameters gets out of range the vehicle will simply cease powered flight.
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.
Incorrect it failed asymmetricaly in such a way that would pitch the vehicle in circles. Normally the sea level raptors are turned off and the space raptors are slowly brought down together.
Right, I just watched it again and it didn’t look normal.
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.