It was strange. I missed the first part of the interaction, when the crows attacked him, but my sister saw it. She said a whole bunch of crows ganged up on the big guy and tore at him with beaks and claws. When I tuned in, the big guy was seriously hurt. His left wing hung unfurled on the ground and he was dragging it as he tried to get away. He was literally stumbling and could hardly walk.
All the while, Crow was stalking him. A lot of crows were in on this but Crow was clearly their leader. He followed the hurt crow, staying about 12 feet behind him. In the end, the large crow disappeared behind a line of bushes, and Crow followed him around the bend. I assume they ripped the big guy to pieces at some point, and ate the good parts.
My sister was worried. She thought this behavior meant there was something "wrong" with the bird population. But I knew it was just nature in action. The big guy undoubtedly pissed Crow off by violating the Code of the Crow. You never want to do that because the punishment is death.
This doesn't change my opinion of Crow. He's my friend. And he's a murderer. It's what crows do.