In the first episode where the leader of Red Flag, Anna, was introduced, it was said that she was not able to communicate with anyone. She was unresponsive and unable to answer anyone, before it was revealed that she communicated through making sounds.
In a later episode, where Gary sneaked off to secretly meet her, he was guided to Anna's side by her "bodyguard. She then sent the guard away by nodding at him.
I thought she wasn't able to communicate!?!