Far more likely, there's a bug in an interrupt handler that corrupts memory used by the throttle position servo.
If they forgot to put a lock around a read-modify-write operation, it could get hit under unexpected operating conditions, that could be triggered by cosmic rays, ie a memory access exception handler routine.
The brake failure could be caused by the anti-lock system, but that's always a separate processor.
Having that fail in a no-brakes mode, and the throttle fail in a wide open mode, seems really improbable since both sorts of failures are worst case and would imply some sort of interaction between the engine controls and the braking system. Those should be totally independent systems.