The fact that she mentioned dealing with an investigative journalist IN Russia doesn’t seem like an accident; she’s likely digging deeper into his past.
However, astute Arrow fans will likely remember that Susan Williams isn’t the most trustworthy character.
To the outside observer, that clip probably looks like little more than a simple dialogue scene.
She has proven time and time again that she’s an effective journalist, so with enough time it seems entirely plausible that she could eventually uncover his identity as Green Arrow.