Oh, and this hit/block is forward - like in Aikido, not sideways - like in Karate.
The block that Rubert described is similar (I think) to what I do and what we did in the senshusei course. It took a lot of time and many bruises to be able to do it so that it doesn't hurt me any more. (I would be impressed if Rupert can really teach someone to do it in 30 seconds.)
The block is complete "aiki" because you are taking uke's balance and redirecting his striking power to the outside. I do it forward and to the side or just to the side - it doesn't matter much.
From what I can tell the instructor in the video is doing the same movement - he is moving into the strike, turning his wrist/forearm out at the point of the strike, and taking ukes power.