The hand written letters have mistakes and flow that are perfectly imperfect. Also it looks like despite all their effort, they still went able to get the robot to anywhere near replicating human level writing in even a short note.
I'm a bit dubious about 'hand writing experts'. Have their skills actually been properly tested in a meaningful way?
the expert in question has written books on the topic, and consulted to US government agencies like CIA. I think he has some credibility.
Credibility and veracity are not the same thing. You can be a world class authority in something that is completely bogus.
At the end of the video a handwriting expert who worked for the FBI to detect fraud had this to say about the project:
> If I didn't know any better, it could be an actual writing by an individual not a machine.