His name is Matt Moore. He was on an episode in the first season in one of Jack's flashbacks. The one where Jack's dad was operating after he was drinking. Matt played the guy who Jack had to tell that his wife died. You couldn't really see him in that one. Then in the second season he played somebody in one of Ana Lucia's flahsbacks. He was the guy who was arguing with the lady with the baby, and he threw a tv out the window. He also looks like Adam Sandler. Adam Sandler even thinks so. But I think they tried to cover that up a little in Ana Lucia's flashback.