User blog comment:AYET/The yet-unknowns/@comment-4605926-20130105163131/@comment-4605926-20130107101513

Leaving the revolutionaries and joining the Shichibukai.

Agreeing to give himself entirely to the World Government by abandoning his free will, even though he has not even obeyed them blindly prior to the agreement.

Deciding the Straw Hats were of great importance and deciding that the protection of their ship will be his last free will wish.

Maybe some more that don't come up my mind right now, but these are rather significant decisions.