Granted, the steering column probably would not have locked. If the same situation should arise again I would still opt for maneuvering the vehicle to a safe location and shutting down there rather than cut the engine in the middle of heavy expressway traffic.
I'm wondering why no one has brought up the issue of a fail-safe for these types of devices. When the electronics continues to partially work (maintaining current speed but ignoring user input ) the fail-safe should detect this condition and release throttle control.