Holmes and Watson drop the incredibly valuable treasures off at the police station, where Gregson is uncomfortable about this whole thing. They just coincidentally found Le Chevalier's stuff? Right after searching for Le Chevalier? That is their store. And Holmes is not leaving the art tube (which obviously contains the Pieta) with the police; he's taking it home instead.
At the Brownstone, Watson is not okay with Holmes hanging a stolen fifty million dollar painting in their living room. Holmes figures he might as well have a masterpiece around while he studying court transcripts. He promises to bring it back tomorrow. Watson's phone, which is on the mantel for some reason, rings. It's her brother Oren! If this were the IMDB Trivia section, Ids have something about how Lucy Liu player O-Ren Ishii in Kill Bill. Apparently she texted him to say she was coming to dinner with her client. Which means, of course, that Holmes did it. They've been pretty consistent with Holmes's trait of putting things away in weird places. Remember that time he left a bag of chips on the top shelf of a bookcase? Watson complains that she had a code on her phone to keep Holmes out, but Holmes points out that obviously a four-digit code wouldn't present him any problems. She wants to leave him alone, Holmes says "relapse" to force her to keep him around.
The next morning, Holmes has coffee, yogurt and fruit for Watson, who is still in bed. They're going to the Property Clerk's Office, because that's where they keep Exhibit C. It's just a handwritten note with the names of the criminals next to their coffee orders, but the jury looked at it three times. At the trial, it was just proof that the criminals knew each other.
Holmes shows Watson the paper. Here are their orders: Justin, Grand 2 Sugars; Alex, Cai soy latte; Jeremy, Coffee soy; Amelie, Van. soy latte. I'm going to come back to this order in a few paragraphs, so I want you to notice the names. Justin, Alex, Jeremy, and Amelie. Watson notices that there are three soy drinks, which is kind of a high ratio. But Holmes is more interested in some gibberish on the back of the paper. It's Malboge, which is a computer language that's supposed to be impenetrable. But Holmes has a contact who knows it. His theory is that someone from the jury recognized it as computer code and figured out how to use it to break the safe's encryption. And on looking through the jury records, he settles on Justin Guthrie, who was a former software engineer.