Although the movie takes place in Australia and everyone speaks with an Australian accent, Jude, played by Australian actor Ryan Kwanten, is the only character in the film that inexplicably speaks with an American accent.
A few minutes in, a robotic voice announces that oxygen levels are at 3.3% (normal is 21%). Then a few minutes later a protestor immolates himself. However an open fire wouldn't burn in only 3.3% oxygen. All of the shots of forests and buildings burning would be impossible for the same reason.
The desperate worker who asks for time off and is then let go in the opening minutes of the movie is played by actor Andy McPhee, father of actor, and star of the movie, Kodi Smit-McPhee who plays the part of worker Ethan Whyte. Kodi's character Ethan is also the worker who subsequently takes his shift and, by default, his job.