Oliver and Diggle confer in this scene from "Blast Radius." It's the first Arrow episode of 2014.
Added:

Arrow Season 2 Episode 10 Quotes

Sara: Ivo killed Shado. He’s the one that pulled the trigger.
Oliver: Because I chose to save you. He needs to know the truth

Diggle: I've just never seen you spooked like this before.
Oliver: That should tell you something.