There are no documented instances of a wild orca knowingly attacking a human. In the handful of cases where a wild orca has acted violently all ended once the orca recognized that it was dealing with a human rather than a seal or some other prey animal. We don't really know what orcas think about humans, but they seem to consciously avoid harming us. Like other dolphins they have a language and culture, even names for each other, so who knows what their myths say about humans. In this case I have no doubt the orcas knew how they could have gotten to the penguin, but they decided not to.