Re: the scene in which Mike asks Hyman Roth who was behind the killing of Frank Pentangeli -

Roth looks at Michael strangely. Was this because Roth was pissed that Mike had the nerve to ask "who gave permission" (for the hit), OR was the look due to Roth's surprise when he realized Mike thought Pentangeli was dead??

I think neither.

I've noticed the surprised look on Roth's face, and the "caught by surprise" inflection in his voice when he says "Why...the Rosato Brothers".
I always thought that he was scared when Michael asked, since it was known (Willi Cicci lived to tell the tale) that the Rosatos did it. Roth wasn't so much surprised as he was nervous that Michael was suspicious.

I always thought it was cos Roth was pissed at Mike for even daring to ask that question like it was business and what gave him the right to question a man like himself, the great Hyman Roth.
The way Roth glances at Johnny Ola always seemed to re-inforce that for me, he looks at him as if to say 'can you believe this little punk'
The speech he goes on to give Mike

There was this kid I grew up with -- he was younger than me. Sorta looked up to me -- you know. We did our first work together -- worked our way out of the street. Things were good, we made the most of it. During Prohibition -- we ran molasses into Canada -- made a fortune -- you father, too. As much as anyone, I loved him -- and trusted him. Later on he had an idea -- to build a city out of a desert stop-over for GI's on the way to the West Coast. That kid's name was Moe Green -- and the city he invented was Las Vegas. This was a great man -- a man of vision and guts. And there isn't even a plaque -- or a signpost -- or a statue of him in that town! Someone put a bullet through his eye. No one knows who gave the order -- when I heard it, I wasn't angry; I knew Moe -- I knew he was head-strong, talking loud, saying stupid things. So when he turned up dead -- I let it go. And I said to myself, this is the business we've chosen -- I didn't ask who gave the order -- because it had nothing to do with business

seems to me like a 'how dare you question me?' speech to Mike!! : only my opinion, for what it's worth But I am gonna have to rethink this now....

FH

That speech alone was worth the Academy Award. It's one of my two or three favorites

It was one of the better ones of the trilogy, next to Michael and Vito in the garden.

I agree with FH--it was a "how dare you" look. Also, it's my theory that, though Michael left Roth in Miami with the impression that he was going to kill Pentangeli, Michael instead dispatched Pentangeli to patch up his differences with the Rosatos. Roth must have been very worried that Michael no longer suspected Pentangeli in the Tahoe shooting--and might have been suspecting Roth. So Roth had Pentangeli killed to get rid of a Michael-ally and to keep Frankie from cooking up more mischief with Michael. Roth disguised his real motive for killing Pentangeli in that world-beating speech about Moe Green. It was his way of telling Michael that the killing of Pentangeli was a quid pro quo for Michael's killing of Moe Green. And, plawrence, I agree: that was Strasberg's Oscar right then and there.

Did Hyman Roth know Michael was BS-ing when he said "Frank Pentangeli was a dead man"? I never understood why, if Roth though Michael was going to kill Pentangeli, did he have his Rozzato Bros. attempt to whack him instead?

Roth was happy that Michael said "Frank Pentangeli is a dead man" because it seemed to indicate that Michael blamed Frankie, not Roth, for the Tahoe attack. In fact, Roth saw a silver lining in the cloud of the botched assassination: Michael would kill the obstreperous Frankie without his having to lift a finger or spend a dime! But, instead of killing Frankie, Michael dispatched him to settle his problems with the Rosato Brothers. Oh-oh!!! Roth knew Michael would never give a pass to a mortal enemy. Now he knew that Michael didn't suspect Frankie in the Tahoe attack, leading to the possibility that he did suspect Roth.
What to do?

Roth ordered the Rosatos to kill Frankie at their meeting. That way, he'd eliminate Michael's ally before the two of them could cook up any mischief against him. To maintain his façade, Roth could always claim that he’s only done what Michael said he was going to do anyway.

Roth was insulted with Mike's questioning, as he felt that he was getting no respect. Also I find it interesting how Roth was on his deathbed, yet he thought he could live forever, as Michael points this out.

I always felt that Roth's answer " The Rosatto Brothers" was an act of playing dumb to mike, to hide his guilt, like trying to say "What are you asking me for? I have no idea.". Then I believe that Roth, being an intelligent man, instantly realizes that Mike just doesn't buy his answer, so he goes into the famous speech about Moe Green. Yes, I agree, that speech was definately acadamy award material.

Don Cardi