Well, there's the bit in Sold Down the River Shaw saying "as much as I like Sefton you got to admit reliable ain't the word that springs most skeedaciously to mindwhen his name is mentionned", which on top of Shaw admitting to liking Hannibal tells me that he has a pretty good estimate of his character despite, as you say not having interacted much in Ben's presence or Ben having talked much to Shaw about Hannibal.
Then there's the opening scene of Chapter 23 in Die upon a Kiss where Shaw gives Hannibal his coat, but not before sending Calvert out of the room. In that same scene, he gets to his feet as soon as he sees Hannibal is hurt, calls him and Ben 'Maestri' and calls Hannibal his friend, something he wouldn't do if their only acquaintance was through Ben.
Despite this, Shaw keeps calling Hannibal 'your pal Sefton' (like in Dead and Buried) in Ben's hearing, which is oddly distancing. Why the insistence that Hannibal is Ben's friend, not Shaw's? Especially since when Hannibal is hurt he does call him his friend.
An exercise in making a mountain out of a anthill
Then there's the opening scene of Chapter 23 in Die upon a Kiss where Shaw gives Hannibal his coat, but not before sending Calvert out of the room. In that same scene, he gets to his feet as soon as he sees Hannibal is hurt, calls him and Ben 'Maestri' and calls Hannibal his friend, something he wouldn't do if their only acquaintance was through Ben.
Despite this, Shaw keeps calling Hannibal 'your pal Sefton' (like in Dead and Buried) in Ben's hearing, which is oddly distancing. Why the insistence that Hannibal is Ben's friend, not Shaw's? Especially since when Hannibal is hurt he does call him his friend.