Jack told Ben that thats what Locke told him happend to the people on the island after the 06 left..

i dont recall Locke saying anything like that

Uh oh. You could be onto something.

I kept waiting for Locke to bring it up too. I thought that was going to be the info that sent Jack over the edge.

Locke did say something like that to Kate though, right? He informed her that everyone would die if she didn't go back, so maybe somehow the information got to Jack that way? I don't know...

Good catch, I didn't think about that.

From the Season 4 Finale:
JACK: He told me... that after I left the island, some very bad things happened. And he told me that it was my fault for leaving. And he said that I had to come back.

From the Season 5 Premiere:
JACK: Sawyer, Juliet, everyone from the boat... and everyone we left behind--John said that they'd die, too, if I didn't come back.

Did Locke tell him any of this?
The stuff John told Kate, didn't he throw in the guilt trip stuff after Mathew Abbandon told John to "step it up"? John was just laying it on thick to get them to come back?

Even if Kate told Jack about how John told her that if they didn't go back everyone they left behind would die.. where did the whole its all Jacks fault thing come from?

Even if Kate told Jack about how John told her that if they didn't go back everyone they left behind would die.. where did the whole its all Jacks fault thing come from?

I don't know that I believe the whole Kate-told-Jack thing myself, but a lot of Locke and Kate's exchange was off-screen, wasn't it? Didn't it open with her saying she wasn't going back? I'm trying to remember but everything's a little fuzzy. But if that's the case we could assume a number of things about what Locke told her, I suppose.

EDITED TO ADD: It just occured to me that that still doesn't explain Jack saying that Locke told HIM specifically... so I don't know.

Hm... maybe one of Jack's hallucinations of his father said something to this effect, and he associated it with Locke since Locke mentioned Christian? That's the best I can do. :-/

Of course, it could just be what Jack believes himself, with his whole perma-leader mentality, and he needed an answer to give Ben. Maybe he was ashamed to admit that he had actually acted quite rudely to Locke, and made up this exchange that was more in line with his own guilt.

Maybe we will see another episode with Locke visiting the Oceanic 6, and trying to convince them to go back. But, um, yeah... probably not.

The writers are more likely just paying less attention to these details as the shows grows even more complicated. They are screwing up.

There could be more to Kate and Locke's conversation; it did seem cut short. I thought the exchanges with the 06 were all pretty disappointing, other than Sayid's new calling and talking about Nadia and Kate telling Locke that she had "thought" about him a lot.

Perhaps there could be further scenes between Locke and Jack? Locke could have been in the hospital for a few days, and so Jack could easily have seen him again before his release. I can't imagine we'd get another scene like that though, but maybe? In the next Jack episode they could flesh it out a bit more. There are definitely some holes between what Jack said Locke told him and what we saw tonight.

They probably saw each other again in the hospital, but the conversation was exactly like Jack already said in the S4 finale and S5 premiere, so we didn't need to see it exactly.