As a manager, if you see one of your directs singeling out one of his emoloyees, it is your job to find out why. That includes talking to the employee. And because caste is so hard to grasp for non-Indians talks like the one cancelled by Google are so important.

Maybe I have a different view on that, we German's are quite sensitive when it comes to anti-semitism. And as woth caste, if religion is never openly discussed, I have no idea how to spot a jewish co-worker. If that jewish co-worker would complain about about being discriminated, it's more than reasonable to follow up. Same goes for caste. It is up to the employer to create an environment where employees can raise those kinds of concerns openly, most fail. Honestly trying so actually goes along way.