The accents are perfect. Sharlto Copley who plays Wikus van der Merwe was born in Jhb.
The funniest bit for me is where he arrives home, his house is in darkness because the family are throwing him a surprise party, and he walks through the door and says to his wife "Why are the lights off? Is the power off? (there were lots of power cuts here around that time – it's better now though) I need to get to the toilet baby – I think might have crapped in my pants . . ." then the lights come on "Surprise!!!".
The underlying story is based on people here being forcibly moved from squatter camps etc under the previous government system.