Isnt there also a difference in the scenes after Hagen leaaves? I seem to recall in the Saga version that there is a specific meeting about how to deal with Woltz, and Vito specifically says not to use the information about his relationship with the girl, after which the horse head thing ensues. I think in the film they cut that part out and only talk about Solozzo in the meeting.
There is a deleted scene following the Woltz dinner--a good one, too. It starts with Connie and Carlo fighting in the Don's house in the mall. Mama says, "Connie and Carlo are always fighting," Sonny gets up to "teach that brother in law of mine a lesson," and Vito pulls him down--"never interfere between a man and his wife...your place is here with Tom and me." He then asks Tom about the Woltz meeting, saying, "...is it true about the young starlet..." When Tom acknowledges it, he says, "infamia, infamia..." Then he asks if Woltz has balls. "Fuggeddabout it," says Tom.
That's a long way of saying that the Janie thing does come up in that scene, but there's no specific mention of not using it against Woltz.
