The one judge who voted against everything:

Her dissenting opinion concluded that the dispute in question was essentially political rather than legal and there was no plausible basis for finding genocidal intent on the part of Israel.

That phrase "genocidal intent" is interesting, and not something I think is reflected in international law. The actual case is summarised as:

South Africa considers Israel to be responsible for committing genocide in Gaza and for failing to prevent and punish genocidal acts. South Africa contends that Israel has also violated other obligations under the Genocide Convention, including those concerning “conspiracy to commit genocide, direct and public incitement to genocide, attempted genocide and complicity in genocide

In any case, this decision is an initial stage about Israel's obligation to PREVENT genocide. So the dissent is not actually relevant until later, right?