Tao is studying his PC monitor wearing his eye glasses moments before Rusty tells the squad he has something to say. When he asks if his being gay would bother them, Tao turns around to face Rusty, puts his eye glasses on, although not enough time has elapsed for him to take them off and says, "You're gay?"
While the FBI would work with the LAPD on such a case, but a case involving a diplomat as this would definitely have the State Dept and its Diplomatic Security Services be involved as well. All law enforcement agencies have a 24 hour hotline to the State Department for any issues involving diplomats exactly for situations like this.