Plenty of people watch Lost. And plenty of people who watch Lost could care less about how one goes about deciphering the runes on the Temple walls, or reading theories about the origins of Jacob and Man-in-black’s conflict as a dramatic evocation of a drunken argument between Kierkegaard and Flannery O’Connor concerning the capacity of men to be redeemed in the eyes of something greater than men. But...they do care about exactly who shot, stabbed, thunked on the back of the head, strangled, or otherwise attempted to murder someone else.
Sometimes we learn the culprit of such an act in the same episode the offense occurred—like when Charlie knocked out Sun in ‘The Long Con’. Sometimes it takes a couple of episodes for the mystery to be solved, as when John eventually confesses to Sayid that it was he who knocked him out during the attempt to triangulate the radio tower. And sometimes it takes a season and a half, a la the interval between learning that Locke was dead, and eventually learning who was responsible. Well, there remains one festering, unsolved shooting that we’ve yet to get a clue on: The outrigger shootings of ‘The Little Prince’. But, But…I have a theory!
I will now predict who was responsible for shooting at Sawyer, Locke, Juliet, et al as they rowed toward the Orchid (this is recapitulated from a comment made here): I think we’ve been given enough clues (in the episode ‘Lighthouse’) to solve this mystery: I propose that Claire was in the pursuing outrigger that opened fire on Locke, Sawyer, and Co. when they were attempting to row to the Orchid Station, and it was Claire whom Juliet hit when she returned fire.
Jin uncovers the first clue during his brief perusal of Claire's tent before she comes back with the still-alive Justin. He's only able to poke around in Krazy Klaire's Kreepshow Karriage by using an oar as a crutch. I didn't catch it on the first viewing, but on my rewatch it scanned as not random right away, cuz this was one symbol heavy episode. In the next scene, Claire tells Jin he was lucky she was here to patch him up, not like the time she stitched herself up after she was shot, she claims by the others, in her left thigh.
If, as [another commenter] suggested, Flocke came into existence on the island 3 years before 316 landed, he may have been one of the others on the outrigger with Claire.
As far as why she might shoot at the Lefties, I’d recall that Claire doesn't seem to need a reason to kill Others. If she was deceived into believing, or simply assumed, that Others were on the boat, I've no problem believing she'd shoot to kill. As to why MiB would specifically advise Claire to shoot at the boat, I can think of nothing. The shooting didn't force the Lefties to do anything crucial that might fit into some kind of time loop stratagem—a la the compass—and the flash back to Rosseauvian times occurred next.
So, that's my case for the 'Claire-shooter' theory. However, there’s considerable evidence against it in the same Season 5 episode. Sawyer finds an Ajira water bottle in the outrigger on the beach. Now, if we take the presence of the Ajira bottle in the outrigger to date this flash to post 316 landing (I'm surprised, but Lostpedia lists the exact date of 316's departure as unknown, but taking place sometime in 2007) we might think the flash these events occurred in was in 2007. But—remember the instantaneous night to day transition 316 makes during its descent to Hydra Island? Could 316 have taken off in 2007, but descended onto hydra island at the same instant the island moved through spacetime, thus landing at some other time than 2007? It’s conceivable, but I think a couple of now-revealed S6 pieces of information limit any possible 316 timeshift from its L.A. 2007 takeoff timeframe to the 30-odd minutes that Faraday recorded in his 'launch the payload' experiments. This puts the Lefties (unknown to them) setting off to row toward the Orchid in 2007. Their camp is pretty decrepit, conceivably the result of 3 years of decay.
If it was Claire & 'friends' shooting at the Lefties, she would've been injured, at most, just days previous to her run-in with Jin. Obviously, this wouldn’t be enough time to heal from the wound. Still, I'd be really, really surprised if we didn't have a Claire-centric flashback episode later this season, so let's hope we find out more about her past 3 years on the island!
THE OUTRIGGER SHOOTING DOSSIER: QUESTIONS:
1. Who was the culprit in the outrigger shootings? Why did they fire on the Lefties?
2. Was one of the shooters wounded? Who?
3. When did the shootings take place?