Continuity mistake: When Martha is searching for how the Daleks changed the design of the Empire State Building, she is examining the plans for the top of the tower. In the first shot where the new plans are visible, the upper right shows a more detailed picture of a plate of Dalekanium. Seconds later, when we can see the new plans again, it's the same side view but the enlarged picture of the plate with the Dalek bumps is gone. These are still the same new plans (the old plans are on her right) and there was no time or reason for Martha to take another page. (00:24:40)
Other mistake: After the hybrid Dalek Sec explains the Daleks' plan to harness the power of a solar flare to the Doctor, when the Doctor asks how many minutes until the flare arrives, Sec says it's in 11 minutes. A fair amount of action and backstabbing later, when the Doctor and Laszlo arrive at the top floor of the Empire State Building and after the Daleks take back control of the elevator, the Doctor says that the solar flare arrives in 6 minutes. It is a considerable stretch for everything that happens between those two moments to take place in only five minutes.