Still not a perfect analogy. If the robot spews copyrighted content, the robot, its owner and the content receiver are now in trouble.

Why the content receiver? That would be like a musician suing viewers for listening to their copyrighted music playing in the background of Youtube videos. It's the responsibility of people disseminating content to ensure they have the right to do so. That's why file sharing cases focus on the sharing, not the downloading per se.

I was under the idea that possession is still punishable, even if it is not given the same severity as infringeme

Edit: I mean not the act of listening, but the act of storing unlicensed material