Ui also witnessed Kaneki's quinque training.
If anything, it's the results that matter and Kaneki handled it nicely by quickly confirming the information on Tsukiyama & Aogiri's connections.
He didn't hesitate and they still view him as Haise Sasaki (for now). After-all, he's a great actor.
So they'll just write "and then he had a snack" on the final report and shrug it off.