Two things:
a) you can definitely capture part of your morals in law, like "don't kill". Our anti-genocide legal system is built for this purpose and applies to corporations as well as to individuals.
b) at the time of the Apartheid, unlike during WWII, crimes against humanity were already prosecutable "anywhere on earth". In other words we can definitely prosecute IBM now for a crime they committed under a law that was already active when the crime was committed, and which has no statute of limitation.