Detailed Explanation of the IJF Judo Refereeing Rules
Breaking the grips with one or two hands and immediately taking grips is allowed. Breaking grips with one or two hands and not taking a grip immediately is shido.
Breaking the grip, as long as after that a grip is still there, is allowed.
For example, if the judoka in blue judogi has one grip and the judoka in white judogi decides to break with one or two hands, white should keep at least one grip in his/her hand(s).
Mathematically, it's simple, if blue has one grip (1-0 blue), after breaking, white shall keep at least one grip (1-0 white).
With this decision we would like to offer athletes the chance to change grip in order to perform techniques.
On the opposite side, if after breaking the grip, white does not have any grip anymore, it is shido.
No shido because no separation between the athletes
Shido white given because separation between the athletes