英语翻译Customs and Border Protection analysts added Mr.Shahzad'

英语翻译
Customs and Border Protection analysts added Mr.Shahzad's name to a watchlist as early as Sunday and were monitoring outbound flights from the U.S.Agents were authorized to order a flight to return to the ground as a fail-safe measure,she said.
我觉得剩下的就难了啊
were authorized 的逻辑主语在哪里呢