Remember when Geary meets with Michael and reveals that he has sources that have exposed Michael's proposed takeover of the Tropigala? I wonder if Geary's source was Fredo. Of course, unless I missed it, I don't think the film reveals a link between Geary and Roth.
Geary's source was Turnbull, because, after Geary tells Michael that his move will leave him with a "technical problem...the license will be in Klingman's name," Michael immediately replies, "Turnbull is a good man."