I am thinking that this whole episode was to show how messed up Jack became as a result of 1. losing his wife & 2. being the cause of his Dad going back to drinking. Sarah said Jack's Dad was drunk when he called her to help Jack out of jail that she could hardly understand him. But he had been sober for 50 days. We saw Jack already losing it over Sarah divorcing him, so my whole theory is that this episode is the prequel to show us how Jack is NOT a good guy. His tatoo is from Bangkok (if I remember right), he can shoot better than Kate (ie: when they were in the net), he has a bad bedside manner (according to Hurley) and he has an obsession to make sure everyone is all right (maybe making up for a time in his life where he dismissed the value for human life).

I can't wait to see the flashback of his dark side! ;P

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"See you in another life, brother." -Desmond