Electric servos for steering wheels use safety critical code, with lot of safety checks, and use direct drive. No need for silly patent for common sense out of the United States.
Those safety checks need to be run continously, actually, or the software will not get the certifications necessary to be released on the roads. There are passive means: practices and coding guidelines, static checks, but also active measures: defensive coding, redundancy, continously active safety check logics.
So my original point was: it doesn't matter if you use direct drive or a transmission, as both will be controlled by software, and ultimately the safety of that software will determine whether the System is safe overall. The same design principles and safeguards will need to be implemented in both cases to provide the needed integrity.
But I doubt there are any patents on this. I guess it would be illogical to demand vendors to use patents by someone. But there are lots safety regulations on the topic.