It was in last night's ep when Sarah came into the ER. The guy she hit was named Adam Rutherford, who I assume is Shannon's dad. During the scene you could hear snippets of the other side of the room like the time of dead being 8:15. Jack's dad was called to ER, but didn't arrive, presummably he was out getting his drink on too. To me it seemed like Jack made the decision to work on Sarah instead of the other man, but in the end his dead was a bunch of people's faults. :)