Who knows?
But...pissed or not, Roth's 'This is the business we've chosen' speech is to me a pretty good indication of how these things were looked at. It wasn't the killing of Moe Green that pissed Roth, it Michael Corleone's inquiring as to who ordered the hit on Pentangelli. The former was business; the latter was not.

As any regular on the board knows, I haven't read the novel...but it makes perfect sense that Puzo would intertwine his fictional characters with their real-life counterparts of the same era. At the same time, I feel it was wise to omit them from the film, where their presense wasn't needed.

Apple