And we don't know how it would have gone if he'd told the SID... maybe Zhu Jiu would have taken the opportunity to do something worse?

Oh, sure, I'm not running the Recall The Envoy campaign. :) Just, lying to Zhao Yunlan was imo the wrong professional call, and I might have been cross if the narrative hadn't called him on it.

You're right that there wasn't much of a shocked reaction. But if you think of possible reactions... once they heard about the rape, I also don't recall anyone doubting the professor or telling her she was reckless or anything - I'll take that! :)