Continuity mistake: When Amy puts on her poncho and says "If we're all gonna die, let's die looking like a Peruvian folk band", the slit changes orientation between shots as she walks to stand between the Doctor and Rory; from across her shoulders to pointing downwards. And no, she doesn't adjust the poncho onscreen to account for this. (00:27:35)
Plot hole: When the Doctor realises that something is coming up from below ground, he tells Nasreen and Tony that at the speed the three transports are coming, the underground arrivals will reach the surface in 12 minutes. The rushed preparations that ensue, including hurrying from the drill hall to the old church and setting up a surveillance network outside, couldn't have taken less than 12 minutes to set up, especially given that they also had to: inform the others trapped inside the shield (Rory, Ambrose and Elliot), inform Rory and Ambrose that their significant others (Amy and Mo) were missing, run between the old church and the block of houses and gather supplies. And, lest we forget, there's also Rory and the Doctor arguing about what happened to Amy and Ambrose's initial skepticism as to what is occurring.
Continuity mistake: When the Doctor stands between Restac and his fleeing companions, using his sonic screwdriver to disable the Silurians' weapons, as the camera angle changes, the Doctor's grip on the screwdriver switches back and forth between pointing it at the lizards and holding it straight up and down, á la the Neuralizer from Men in Black. (00:30:30)
Continuity mistake: Near the end, when the Doctor is explaining to Amy that she will forget Rory when the crack in time is finished eating him because he's part of her personal timeline, and he has his hands on her temples, Amy's hair is covering her ears in some shots, but not others. (00:40:56)
Continuity mistake: At the beginning, when the Doctor takes Amy to planet One, he holds out his hand for Amy to take hold of when they're about to leave the TARDIS. When you see her from the back, Amy lifts her hand wearing her red fingerless gloves. But when it switches shot and faces Amy from the front, she takes the Doctor's hand wearing no gloves. When she steps out of the TARDIS, her gloves are on again. (00:04:54)