When River first shoots at the astronaut she fires her gun one-handed, with her other arm hanging at her side. In the very next shot, she's firing her gun with one hand and cocking it frantically with her other.
The Doctor leaves the picnic with a bottle of wine, but when the shot flicks back to him, the wine bottle is gone and is not visible on the shore.
When the little girl is wearing the space suit and meets Amy, she lifts up the visor. There is a bullet hole in the face glass. After the little girl removes the space suit and it is lying on the floor, there is no longer a bullet hole in the face glass.
The Doctor leaves the invisible TARDIS via the right door, but arrives in the Oval Office after exiting the left.
When the Doctor is standing in the doorway of the TARDIS about to enter the Oval Office, you can see outside that it is pitch black. When the shot changes to inside the Oval Office, it is being lit by several lights around the room, and therefore not pitch black.
The desk that President Nixon was sitting at, in the Oval Office, lacked the panel, with the Seal of the United States, that President Franklin Delano Roosevelt had installed on the front of the desk, to conceal his wheelchair.
The Doctor states the space men (astronauts) live in Florida. In fact they live in and around Houston, Texas.
The Secret Service agents on the President's detail are depicted using revolvers, but by 1969 the Secret Service had transitioned to the Colt M1911 semi-automatic pistol.
When the old version of Canton Everett Delaware drives up to the Doctor's picnic on the beach in 2011, a Diesel engine badge can be seen on the side of his truck. However, the sound of his engine is clearly not that of a diesel engine.
When the astronaut first meets the doctor and slides open the solar visor of his helmet, there is a hissing sound effect of air escaping. No such sound can occur since the solar visor is not pressurized. The entire helmet with the sun visor was just extra protection. Apollo astronauts wore a "fishbowl" helmet beneath it and only that one had air fed into it.
While the street names are in Cape Canaveral, all the presidential streets run parallel and do not intersect.
The location listed on Amy and Rory's invitation is 37º0'38" N, 110º14'34", which is atop Oljato Mesa in southeastern Utah, USA., about 0.85 miles (1.37 km) north of the Utah-Arizona border. There is no Lake Silencio, nor any other body of water large enough to be a lake nearby; the closest body of water is Lake Powell (a reservoir created by the dammed Colorado River) about 35 miles to the northwest.
After Amy comes out of the restroom the Secret Service agent sees her phone (an unknown device in 1969) but lets her keep it. There is no way a Secret Service agent would let you keep an unknown device around the President. It might be a weapon. It would be even more likely confiscated having been called a "phone" when it clearly is NOT a phone, to someone in 1969.
At one point Canton, an American, says, "How long have Scotland Yard had this?" Unlike British English, American English treats collective singular nouns as singular, not plural. An American would say, "How long HAS Scotland Yard had this?"
The Doctor asks how many Canton Everett Delaware the thirds there can be then says "Well, three, I suppose." There can only be one Canton Everett Delaware the third as the previous 2 wouldn't be the third.
When Amy encounters the Silence in the rest room she takes here eyes off it for a second and doesn't forget it's there.
When the Doctor dies, Canton delivers a red metal can, which Rory identifies as "gasoline". The British, however, call it "petrol".