Clean up your own mess by kastrato

What Jack needs to do is to clean up his own mess.Something simular to what Locke did when he tried to save Eko's life.

On the Flash-sides ,Charlie says to Jack "You should had let that happen man.I was supose to die."

I think Charlie there has his previous consciousness.
He makes a point.He says "I was suppose to die",with this he supports his first setence saying "I was suppose to die and i accepted it,You shouldnt had let that happen..."
I wonder...what was it tha Jack should had let happen.
I am gonna make i wild guess and i will say that Charlie ment something that has not yet happend .Its not something that Jack should had done during the 5 season's of Lost
but something that will take place at season six.And it has to do with the island.Chalie at my opinion says "You should had let the island sink ,Jack-should had let that happen
because now we all must suffer the consequence of your decision and its bad.If my wild guess is correct then i think that Jack will try to save Kate and by that he will mess up
the timelines and will create the loop.