I'm assuming that all the "CCTV" footage is fake and captured by the camera guy and sent to the producers, since I can't think of a legal way for them to have instant access to every ATM's camera (and I doubt that most ATMs as small as the one in the bus station even have a way of remotely viewing the footage).
I'm wondering why the first couple can't just stay at the friend's house for the full 28 days - it's not like the investigators can get a warrant to enter the house. Is there a rule that they have to change locations every couple of days?