Many have brought up the likelihood that Shaka is the one who’s betraying the Strawhats/Vegapunk/Satellites, and between his cryptic nature and strange “flip-flopping” answer to why the cameras aren’t working, I think that’s enough to make him a top candidate.
But what really seals the deal for me is a detail in one of the many beautifully illustrated panels. In particular, this one:
On my first run through (and re-run) I noticed Usopp’s expression, particularly one of concentration and maybe nervousness as he looks behind Shaka at his panel. He’s putting on his goggles which further suggests he’s trying to get a good luck at something.
We may be distracted by all the interactions and details in the background, but Oda makes it front and center what we need to pay attention to. And who better to realize someone’s deception than the King of Lies himself. As such, I think this panel further suggests Shaka is the traitor and that Usopp will be the one to reveal (or at least suggest) that this is indeed the case.
I feel as though we’ve already gotten a few hints already. the first time we Shaka in the manga we see the back of his head. Usually when we see characters with their backs turned, it means they’re hiding something or their allegiance may not be with whom we think it to be.
It’s the same with Stussy/Bukim on the MADS Cover Story. Shaka also wears an outfit that says “caution” on it. There could be a double meaning with this. He also represents “logic”. Maybe working with the World Government is the most logical choice.
Shaka acted surprised whenever CP0 bypassed the port, then acted surprised again when the frontier dome got taken down despite the fact that he’s shown to act rational and calm whenever a Yonkou Crew (Luffy) showed up at his door step. He was also called out for putting up a “Goody” Act by Lillith who is the Evil Vegapunk.
Also, I think Luffy breaking his shoes will actually play a role later on. Shaka was able to block the crew’s movement earlier using their shoes. What if at one point the traitor will block the crew’s movement in the same way but Luffy having broken his shoes will be free to intervene?
Not a coincidence that Luffy broke his shoes, so he can’t be stuck to the floor once Shaka inevitably magnetizes the floor again.