When Amy wakes up in present time her nails are still painted orange as they've been. After greeting her parents and once the scene cuts to her phoning Rory (she's still in her pajamas) her nails are now painted red for the rest of the episode.
When The Doctor goes back to Rory to tell him he should put the screwdriver in Amy's pocket, Amy is clearly breathing in at the beginning of the scene.
When Amy is reading (viewing) the history of the Centurion who guarded the Pandorica Box, the monitor showed an air raid over London in progress. These bombers shown were USAAF B-17s and not German.
Rory as a Roman Centurion from the early 2nd Century is wearing the wrong kind of helmet. Centurion helmets have the crest perpendicular to the line of site, used for signaling line changes.
If all the stars in the universe had gone supernova at the same time, the sky in the year 2010 would be brighter than ever, around the clock, as the light from more and more supernovae would keep arriving in succession, depending on their relative distances. Not only would there not be any night any more, but over time, it would be so much light and other radiation that all life on Earth would have long since been destroyed, and probably the entire planet.
If all the stars in the universe had gone supernova at the same time, most of them would still remain visible and appear unchanged from Earth for a long time, even after thousands and thousands of years, depending on their distance, because the speed of light is constant and thus the light of their supernovae would arrive at Earth at different times, as required by general relativity.
If the sun had gone supernova along with all other stars in the universe (as the Doctor says it did), then that supernova would have completely destroyed the Earth less than eight minutes later.
Around the time when the Doctor is taking the satellite dish off the roof to see if he could use it to hear his TARDIS, you can see a bird fly over. At the point when this happens every other sign of life is gone and they are the only living thing due to the fact that they are all anomalies, so it is impossible for a bird to still exist.
When the Dalek attacks them on the roof there is no way that all 4 of them could have got through the hatch in the 3 seconds of time shown.
Figure can be seen on right side of screen after Amy touches her younger self on the head.
If the destruction of the Tardis meant that the stars never existed then how do the adults know what stars were?
When Rory opens the Pandorica and rescues the Doctor with the sonic screwdriver, the Doctor confirms that it was really future him that gave Rory the screwdriver by touching the two screwdrivers, causing them to spark. He says this is because they're the same object at different points in their timeline.
But later, Amy touches her younger self, Amelia, but no sparks appeared.
But later, Amy touches her younger self, Amelia, but no sparks appeared.