At the beginning the teacher spells metamorphic wrongly as metamophic but then when the pupil stands up and gives his little lecture it is spelled correctly.
The lead on the binoculars used by Kathryn changes from hanging down loose to being wrapped around numerous times.
When the "supply plane" first appear at 00:34:27 it looks like normal C-130 plane which is used for carrying cargo, but when second scene show this plane again it's AC-130 gunship modified version with guns mounted on left side and this plane can't carry cargo.
The placard hung from the ceiling of the museum near the end of the film, detailing that Kate Thompson is a Nobel Prize winner, has her name spelt (British English) incorrectly as THOMSPON.
At around 49:30 into the film, the young boy inspects an American coin. You can't see the date on the coin but the boy says it's from 1797. You can however clearly see that the image on the coin is the Statue of Liberty, which was not completed and dedicated until 1886, almost 100 years later.