Elon Musk and Satya Nadella were both engaged in a public Twitter dispute which is against Twitter’s policy of not engaging in abusive, hostile or provocative behavior.
Musk accused Nadella of violating this policy, claiming that his tweets were not only hostile, but also offensive in nature. While it is not clear whether Musk’s claims have any factual basis, it is clear that Twitter’s policy prohibits such behavior. Therefore, the accusation of policy violation is a valid one.