I think he looks just fine. He's obviously dressing to go clubbing and not for a job interview, so the rules of suits and ties don't apply. I suspect quite a few SF'ers sport similar looks.
Clubbing is recreation for the new generation, some people like it, some people hate it, but the old rules are irrelevant there. Wearing a tie or jacket with a jeans would look odd, and would be make someone feel pretty hot in a club on a summer night.It sounds like 'clubbing' suspends the rules of good taste. At one time people used to dress like a grown up when they went to a bar or restaurant. Now it seems like the staff dress better than the patrons.