Oh yes. He knew. And anyone who thinks otherwise is just wrong. He is a detective first and foremost, as Tarantino stated...He knew, and what's more, he must have regarded her with a certain respect in being able to hide in plain sight like she was, after escaping from the death squad.

He would've know that it must not be easy to keep her cool whilst sitting with the very man who ordered your entire family to be killed.

Then, as if to test her resolve one final time, he says the crack about wanting to ask her about something else, but not being able to remember...after a cold, burtal stare...right into her soul it seemed...
 Ouch!