I don't know this sensei, but this is a video I had seen close to 5-8 years ago. Back then it scifi to me, now out is like "dang that is aikido, he did not give any secret there".
However, at the same time it comes to me that yes it a painless nikkyo, but because he leaves uke free to run away. At the end of his nikkyo the connection disappears. So it is painless because uke is a good uke. If uke was someone really trying to cut nage's head off, would that nikkyo still be painless to be effective?