As you've said it is the word 'unfolding' which needs to be looked at. The linked document suggests crimes against humanity have been committed (and I agree) and these contravene a number of laws around civilian populations and targeting - but it calls upon action to prevent an unfolding genocide.

South Africa has indeed filed a case at the ICJ but that is simply a case. I can file a case against anyone for anything - it is the result of the case that matters. Whether or not it is genocide is to be decided by the UN and it will revolve around 'intent' - Israel will be asked to demonstrate what measures it has taken to curb it's most vociferous war-hawks (who have made pro-genocide statements) and will be asked to provide evidence that it is carrying out a limited war. In short, Israel will be asked to prove they are not targeting every Muslim, every Palestinian or every brown person. Given they are surrounded by Muslim countries, haven't launched an out-and-out war in the West Bank and have plenty of brown people assimilated within their own population I think they can do exactly that - I think the South African case will fall down on the matter of intent.

A much better strategy would be to file cases for specific war crimes, these are more easily proven and have a lower standard of evidence required. And alas, the South Pole doesn't want me, I have to stay here in the UK.