Anons, I think I figured out who 'S' is from the May 2017 game chat.
Here's a State Department "memo" related to the incident, included in court docs.
https://thehill.com/policy/international/469705-erdogan-visit-stirs-memories-of-violent-protests
Nope. Tom Shannon was interim Sec of State in May 2017. Tillerson wasn't in office yet.