Plot hole: The virus ravaged Nyah is making her way to a cliff to kill herself when Ethan sends his buddies to save her. There is no way that the flight to her location would have taken that long unless John Polson decided to take Ving Rhames for a guided tour of the Sydney skyline first just in case he missed any of it. It's just a couple of minutes flight time for a helicopter at full throttle.
Plot hole: In the first night that Nyah is in Ambrose's house she meets with Ethan outside the house and they talk for about 1 1/2 min. Then we find out "Ethan" was really Ambrose with one of those "high-tech" masks. My question...After being in bed with both, how come Nyah didn't recognise Ambrose is about 5 inches taller than Ethan?
Plot hole: Ambrose wants to spread a deadly virus so he can make loads of money selling the cure. To this end, he drops off infected Nyah in the middle of the city to get this going. For this to work it would have to a highly contagious airborne virus. However none of the characters are worried about being near Nyah after she is infected. Even the scientist who created it smuggled it out by infecting himself and then getting on very long commercial flight.