Jack takes of his coat and shirt before going into the radiation room to connect the switches. He is dressed in a white t-shirt and comments that he looks great. Then he comes out, still wearing his white t-shirt while helping the Doctor start takeoff. However, when Martha runs to find Jack and the Doctor, he is wearing his black shirt again UNDER his braces.
When the gates at Silo 16 are opened to let the Doctor into the base, a neon yellow safety jacket is briefly visible in the background through a fence.
In one of the shots in the hunt, in the bottom right corner, the shadow of two cameramen and a camera is clearly visible.
In the Cardiff scene, The Doctor mispronounces the name of the Slitheen as "Slideen."