The ICC is not prosecuting Israel. The ICC prosecutes individuals. South African or the ANC have no saying in who the ICC pursues cases against.
The ICJ is handling a the case against Israel filed by South Africa. The ICJ handles only cases with state parties, and only on the basis of complaints of one of those state parties.
The two cases are entirely separate, and the ICC and ICJ are two entirely different courts. The ICC was created under the Rome Statue. The ICJ, meanwhile was founded on the basis of the UN Charter.
I think ICJ giving credence to South Africa given they consider the ICC optional is still ... unfortunate, at best, but "conflict of interest" is rather less applicable.
The ICJ is handling a the case against Israel filed by South Africa. The ICJ handles only cases with state parties, and only on the basis of complaints of one of those state parties.
The two cases are entirely separate, and the ICC and ICJ are two entirely different courts. The ICC was created under the Rome Statue. The ICJ, meanwhile was founded on the basis of the UN Charter.