First thing,ditch the blades that come with that knife. Replace with Mr. Twister blades. Second thing , cut just above , and go beside the rib cage. No reason to dull your blade for something you are going to cut out anyway.
Happen to have a video showing this? I just cut straight thru like OP, but I've often wondered if there's an easy way to somehow bypass the rib bones. I know it's possible, but is it worth an extra minute when filleting a bunch of them?