Sun stumbles out, leaving Jin to clean up himself and, one presumes, their bathroom, which is beginning to look a lot like the Ewen High School ladies' room after prom. After she goes, Jin finally faces himself in the mirror with a look of shame and horror, and breaks down.
Back in present time on the island, things aren't going much better for him. He's been planted face-first in the sand. Sawyer cuts him loose, and Jin groggily pushes himself up in time to see Michael sprinting at him with murder in his eye. Jack is bearing down on Michael. Fortunately, Hurley steps in to block Michael too. I'm thinking if there's anyone I'd want between me and anyone else, it would be Hurley. Jin looks up as more castaways pour out of the trees. The camerawork is jerky and chaotic. Michael's screaming that Jin burned down his raft, Jack's trying to talk him down (O, Jack! How ironic you have that name when it's so obvious you're the Ralph of the island!) and everyone gradually forms into a loose circle around Jin.
And then we get the coolest narrative effect ever, with the camera shifting to Jin's perspective and lingering on his ear; as this happens, the rapid-fire argument between the English-speaking castaways shifts to a series of shouted syllables. We see the camera swing from person to person; it's a wonderful way to convey how difficult it is to read a situation when you don't get the language, and how you struggle to make sense of the cues. The camera stops swinging wildly, and we follow Jin's gaze to Sun. She's standing on the edge of the crowd, looking horrified and helpless. She keeps looking at him. He keeps focusing on her. Eventually, he speaks.
According to forum poster Fiametta, who kindly sent me the translations for the scenes, Jin says to Sun, "Even you won't believe me?" Ah, man, they teach the actors all sorts of things in the year 2525. Sun doesn't say anything. Michael turns to Sun and demands to know what he said. Jin then speaks to him; he says, "It wasn't me. Not me. Do you get it? It was already burning when I got there. I was burnt when I went to stop the fire." Naturally, Michael concludes that what Jin is saying is, "Yeah, I burned it. And danced to the rhythm of your screams. Because I have it in for you." And he responds accordingly, i.e. goes thermonuclear and invites Jin to say it again. Jin does: "Michael, it wasn't me." And Michael proves that Korean is neither his second language, nor his tenth, by rushing over to Jin and delivering a punch that knocks him to his knees.