Reminds me of an even more remarkable scenario I witnessed years ago at Neah Bay. A pod of killer whales had trapped multiple sea lions outside of Waadah island. There were a bunch of sea lions on the jetty but the whales cut off a group that were trying to return. The adult whales would flip the sea lions similar to the video except I thought it was with their mouths not tail. Once wounded they let the juvenile whales finish them off. This went on for 20-30 min and it was hard to keep track, but I think at least 6 sea lions were killed. We forgot all about fishing while watching this spectacle!