Earlier quoted context omitted.
Disagreed. They were clearly told not to do that and didn't follow their directions. It sounds like a potential safety hazard to me. They could just have reported what you said - they were told not to touch the wheel, and are concerned that in reality this could be a problem because there are too many people for at least one person not to do something dumb, or fall onto while doing something dumb etc.
If there are self driving cars on the road with a "press here to instantly cause an accident" widget fixed to the dash it's a problem regardless. Testing involves trying out exceptional inputs to find out how the system responds.
It's an already-extent but not frequent threat. The main difference is a change in the amount of social pressure to not do this. That change probably makes it worth exploring a little.
If Waymo chooses, those steering actuators have enough oomph to always win.