Out at the snack machine, Holmes is eating the chips that he was supposed to be getting for Watson. The charitable interpretation is that he knew Watson was getting him out of the way. The cruel way to look at it is that this Sherlock Holmes has so little short-term memory that he forgot who the chips were for in the twenty seconds it took him to walk to the machine.
Bell comes out to tell Gregson that the neighbor won't admit to murder and that he wants a lawyer. Is that rare? It seems like most of the time, even when you've caught the actual murderer, they're not going to admit it just because you asked them nicely. The neighbor does claim to have passed a woman on the stairs, but even though he can provide a detailed description, Bell doesn't care. Because obviously he's making it all up. I really question why they called Holmes in on this, since the police all seem to think that this is a simple, open-and-shut case. Also, Bell calls Holmes "Harry Potter" which doesn't work on any level. He and Holmes talk over each other and Gregson eventually decides he'll accept Holmes's request for a sketch artist.
Still in the police station, Watson wants to know if Holmes can get home by himself. It's New York! There's a subway! And I know the makers of this show know that. It's weird. Holmes smugly knows that Watson is meeting a man she's had sex with because she's been careful not to use gendered pronouns when referring to him. And he knows she hasn't had sex recently because of what a study in Belgium said about her walk.
Now Watson is in a restaurant meeting her date. He wins cases for the DA, so you know he's "successful." He wants to know about her current assignment, but she won't talk about her work. He engages in some exposition, saying, "I know we're not together anymore, but..." It turns out that her parents contacted him to contact her, and he expresses their distress that she's no longer a surgeon. They would like him to ask why she's wasting her time being a Sober Companion. She answers, "I'm doing this because I'm actually good at it."
Back at the brownstone, Watson has made coffee, but won't carry it over to Holmes's outstretched cup. He observes that she didn't sleep with her ex. I guess I should add that he says it smugly, but that's kind of Jonny Lee Miller's default attitude on this show. Holmes is going through the autopsy pictures on his computer. He notes that the victim also had a clouding of the cornea. Watson wants to know why Holmes had told Gregson he was calling from Heathrow. The reason is that Gregson wouldn't let Holmes help if he knew he was an addict. That seems kind of obvious, doesn't it?