"Well, you know what they say about the power behind the throne," Cal says. His look is slightly conspiratorial - remember, Obadiah, Cal's family is in politics, he knows how these things really work. (He overplays it just a little, but that's part of the game, too, playing along with the patronizing undertones in Obadiah's comments. He couldn't possibly be fucking with you; he is just a kid, after all.)

He steps back to stand next to Sherlock as he speaks, mirroring the way Sherlock is standing, deliberately creating a physical presentation of a united front. Yes, Obadiah, Sherlock does have a friend.