Unless...(cue ominous music)...Ben can see into the future like Desmond and knew they would need Jack to be there to save Colleen. This might explain why he was captured alone by the Losties...just like Locke in the last episode he is led around the Island by unusual visions, "things he needs to do", even if he doesn't necessarily know why.

__________________
"The Naked Gun!"

Frank Drebin remembers a lost love.

Frank: It's the same old story. Boy finds girl, boy loses girl, girl finds boy, boy forgets girl, boy remembers girl, girls dies in a tragic blimp accident over the Orange Bowl on New Year's Day.

Jane: Goodyear?

Frank: No, the worst.