In the final scene, when all the characters turn & walk away, the admiral has disappeared even though she had been there returning a salute moments before.
At 1:24:24 Chief Phillips exits the helicopter with his rifle in his right hand. in the following scene he is shown from the back and no rifle is present.
When the Lt CMD came in the Prometheus he called everyone Soldiers, they are actually called Sailors, Soldiers are in the Army.
When the Sailor shot the AT-4 at the tentacle two people was crossing his rear path, both would have been killed in the back blast area that would have burned them alive.
When the admiral was on the phone with Chairman Leary, she said that they sat out on foot to retrieve the President, but they were still actively in the Prometheus and trying to triangulate the Pres pod.
The admiral orders all ships to engage the alien spaceship but only the helicopters attack. None of the battleships fire a shot.
At the beginning of the movie Chief Phillips is introduced as Captain Phillips.
Approximately 50 minutes into the movie, Mya calls Chief Phillips SGT Phillips.
At the beginning of the movie Chief Oliver is introduced as Captain Oliver.
Approximately 50 minutes into the movie, LT Plummer calls Chief Oliver SGT Oliver.