I actually don't find that convincing at all. He dismisses the idea of it being castoff as "special pleading", but what else could it be in the galactic rest frame? Same for the size and tumbling: the most reasonable artificial hypothesis was that it was a cast off chunk of solar sail, essentially litter, and that's still completely consistent with the evidence. His best argument was about the possibility of a natural, normal-shaped object just being a lot brighter on one side, but he barely mentioned that for some reason. I'm a lot more convinced that an artificial origin is reasonable to believe.

Thanks for sharing that - it really helped me wrap my mind around both how weird this object is and also the holes in the argument that it's an alien craft.

Thanks for sharing. This is what I was hoping people here claiming he is wrong would provide.