Or so he thought. He didn't know where all those Lanterns were, whether they were in a pitched battle against a strong foe or many light years away from the nearest planet.
Maybe he did leave all of them enough power to survive. Maybe some of them were in bad situations and didn't have enough juice left to reach safety.
There was an arc with Kyle where he meets one of the surviving Lanterns, I think it was when Kyle was lost in space following Zero Hour and blowing up Oa. And my memory is super fuzzy but I don't think all of those ex-Lanterns' friends made it out alive. Could be wrong, of course, and I'm not trying to drag Hal through the mud here. But there's no way he could have had a clue what kind of situation every Lantern was in, and how much power they'd need to get out of it.
Man, this is making me miss Parallax Hal. I know it's not a popular opinion here but Hal was never more interesting or compelling as he was as (pre-space bug) Parallax.
And I had no idea he was the one who sealed everyone on the other side of the Source Wall. I had stopped reading around the start of that whole story.