This scene between Roth and Michael is one of the greatest scenes in all three GF films. There's a lot going on that is unsaid, but which is determined by a careful viewing of it. Basically at this stage of the game IMHO Roth knows that Michael knows that it was Roth who tried to kill him, and he also knows that Michael has to be very careful how he handles this information. Of course he also knows he can still play the Pentangeli card and move Michael out if his assassination plan fails.
By the time Roth made the Moe Greene comments to Michael it was pretty much common knowledge that Micheal gave the order to Kill all the heads of the five families and Moe. Michael had tried to move in on Moe's casino in GF I and Moe refused, and justified his slapping Fredo around. Since a refusal isnt the act of a friend, Michael had the right to move Moe out any way he saw fit. Roth knew that was the business they had chosen, so he let it go. Still Roth is showing rage that Michael killed Roth and he shows great grief at the loss of his protogee. It is a great piece if acting BTW by Lee Strassberg (who in real life was one of Pacino's mentors). Roth is probably also pissed that he like everyone else had underestimated Michael, and IMHO the killing of Moe Green was probably the seed of Roth's long term plan to get rid of Michael. But Roth keeps it all about this one deal by telling Michael he wouldnt want it getting around that Michael was bailing on this deal (a veiled threat) which Michael parries by asking almost rhetorically "who gave the Oder to kill Frank Pentangeli ... I know I didn't." Roth, then brilliantly explodes at Michael about Moe --- which is also a parry because Roth knows Pentangeli is still alive -- so Roth threatens him once more when he says he is going to go take a nap, and when he wakes up if the money is on the table he has a partner and if it isnt he knows he doesnt have one (in other words by the rules of the game Roth would have been within his rights to kill Michael).

Of course by that point Michael was ahead of the game in Cuba cause he'd already made arrangements to get out and Kill Roth.
Of course Roth survived and then Roth went to Plan B, which almost brought Michael down. I think thats what Hagen means by his statement that "Roth really played this beautiffuly."