[Sokka never communicated with Roku as the Avatar. But he was aware of what he did. And it gave Sokka a different sort of context to things that he doubted anyone else really got. Roku killing Sozin, his best friend. What an impact that had. Roku was a villain. For a reason other than the one Aang and Sokka were discussing now.

Damned if he did, damned if he didn't...]

Then we shouldn't tell him. You shouldn't tell him. He's closer to you than any of us. With everything else hanging over his head, I don't think he needs that too, ya know?