From a kuzure-kami-shiho-gatame position one can apply the North-South choke.
This can be finished with the arm in the hold (as in an arm-triangle position), but I have most often seen it demonstrated in BJJ without the arm.2 3 4
Is this choke legal in Judo? Or does it fall afoul of the prohibition against pins which do not trap an arm when controlling the head?1
It is never allowed to hold an osaekomi just around the head/neck without control of at least one arm.
• Sport and Organisation Rules of the IJF (Article 17)