What he's referring to is a scenario where a car's AI has to choose between hitting a pedestrian on the sidewalk and hitting one in the street. When that's written into code, it creates liability. An attorney could find fault with the way the choice was made in a way that might appeal to a jury.
Attorney: "So you car decided to mow down the mother with the stroller rather than the old man?"
Engineer: "It defaulted to not changing direction if the alternate route is obstructed."
Attorney: "But you could have used the car's computer vision system to override that choice if a stroller is present, correct?"
Engineer: "We could have, I suppose."
Attorney: "But you didn't. Why? Because a child's life wasn't worth the extra man-hours to code that contingency?"
Defense: "Objection, your honor..."
...Companies don't want to be involved in anything like this.