Of course Carrie rushes through the train station by herself, which is the perfect Hollywood setup. I wouldnt expect anything less from Homeland. The interesting thing here is, there is no reason for Saul to initially disregard the evidence that Carrie presents him for Allisons word. Especially because we know now that he obviously doesnt trust Allison; he wouldnt have gone to the hospital and grilled her the way that he did if he wasnt suspicious of what she had said. So I dont know why he doesnt at least put the word out tell Dar, tell someone that there is conflicting information, because Allisons word is one thing, but Carrie has provided evidence. I know everyone is tense and everyone is freaking out because its the airport, but this is something where people would take a step back and say, OK, well, maybe this is misdirection, because Allison isnt someone we tend to trust.
But then Carrie throws all good will out the window when she doesnt evacuate the train station after she spots Qasim. There are all these people standing on the platform looking into the tunnel as Carrie runs in with her gun. She didnt say, Hey, go somewhere else! Run away! At that point, you pull a fire alarm thats not an intelligence expert talking, thats common sense. How about saving some peoples lives here? But thats Hollywood theyre setting up the big ending for next weeks season finale.