You could've left. You entered it's habitat with a predator (dog) and it defended itself. "It should've backed off" is exactly what the bird thought of you, it wanted you to leave because it was protecting its own "beloved companion" (eggs, babies, nest, mate, etc.) You just killed a bird with your bare hands because you wanted to use the lake that it lived in.

That's not really admirable, it's selfish. And it amazes me that you think this bird was just fucking with you because....it wanted to? It's just an evil bird who should've learned it's lesson? It's a fuckin bird lol, it doesn't understand what a threat is. You grabbed it's neck and then let go, all that means to the bird is "This thing didn't maim me and it's still in my territory, I need to keep fighting." Exact same thing you thought about your dog.

The actual move is to grab it by it's neck and throw it back in to the lake. That'll teach it that you can kill it without actually killing it.