What was the move hatsumi was put in as a judo instructor?

[kip42]

What was the move that the American WWII vet put Hatsumi in when he was a Judo instructor? I head that he could not get out of this move and it led him to combat styles.

 

[Chris Parker]

Oni Kudaki. He was rather disillusioned that the American GIs could simply "muscle" their way to victory, and thought that martial arts had to have better answers, but found that sport systems tended not to.