I cant think of any clues that would indicate a relationship with the revolutionary army. Although unlikely and farfetched, Ohara incident could be tied with it, since Dragon was looking for Robin.In which case Robin would probably know about his fight as well as his whereabouts.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.” - Terry Prachett
Well yes, actually I can. This is a conversation, it is perfectly reasonable to ask why someone thinks the way they think. Even a hunch must be backed by logic and intuition. There must be some basis for this hunch, no matter how circumstantial. Something Aokiji said, his personality, past events. If it's only a wild guess, or a most desired outcome, that is a reasonable enough answer. Sometimes the rationale behind a prediction is much more interesting than the prediction itself, allowing us to discuss events that actually happened, and maybe seeing things from a new perspective. So I ask again:
Predicting that Aokiji defected to the Revolutionary Army is not unreasonable, but why? Aokiji had fought for the position of Fleet Admiral, putting his life on the line to defeat Akainu. Why, after seeking promotion to the highest office of the Marine, would he immediately turn around and join an organization seeking to destroy that very institution? He resigned because he did not want to serve under his rival. What then would lead anyone to the conclusion, or hunch, that Aokiji hoped to destroy the Marine and World Government. Sengoku joining the Revolutionary Army makes more sense. He actually resigned in anger, when the World Government suppressed the truth about Impel Down, and forbid the Marine from pursuing the Level 6 criminals.
---------- Post added at 04:28 PM ---------- Previous post was at 04:25 PM ----------
How is this so obvious? What if he is acting on his own? What if he mostly has just been minding his business? Couldn't he have been inactive? Maybe he was traveling the world, catching up with old friends. Why is it so obvious he has been doing that one thing, out of all the many possibilities?
Seeing as Kuzan opposed Sakazuki becoming fleet admiral so much, and there's been a mention of the Marines having gained more power, it's possible that Kuzan hates the Marines and WG now. I wouldn't say it was obvious that he's a revolutionary, though.