Curium is correct, I just rewatched the eps, Rau only broadcasted to the "EARTH ALLIANCE Archangel-class Battleship"(Dominion, they were the only ship to react to the message) and said they had a captive they wanted to hand over. No-one knew it was Flay until she started broadcasting on all channels looking for the archangel. Like SFreedom said Bajiru ordered the druggie piloting Calamity to pick her up, which he did reluctantly. During all this Kira was in a state of shock and had to be protected by Asuran. Flay then started talking about the key which entrigued Azrael. Kira then went off to try and get her but he was stopped by Raider and Forbidden.