When they find the freezer with the padlocked hasp and staple, it has been forced open thus pulling the screws out of the freezer. With the padlock in place the screws should still be sticking out of the staple as the padlocked hasp would prevent them being removed. There are no screws present.
In the first Cambridge scene, a character is seen cycling along Senate House Passage with the Senate House on left of shot, and Caius College on right. That means she is cycling directly away from the river. In the next shot she is crossing the river at Garratt Hostel Bridge. That's a total U-turn.