That was what made me think of it! I was reading a synopsis article that mentioned the FLocke/Jack fight and Jack's bleeding neck and I had a major pause. When I first watched the episode, that was just a passing moment in the show in which we had a little instant gratification at seeing the connection between the two universes. It wasn't until after that I remembered the "appendix" scar! (Back when "Lighthouse" aired, I had just figured it was from Juliet too.)