Revealing mistake: During the night surfing scene notice that the sun is evident in the background (look closely it does not appear long). There are also shots where you can see clouds and faint blue sky. Moments later you see Keanu and Lori sitting in the water with completely different lighting which was actually taken at night and further distinguishes that the surfing shots were not actually done at night time. I heard the scene was shot during the day with a filter so it looked like it was shot at night.
Factual error: Australian police are never equipped like they are at the end of this movie. The 1st Police on the scene would be Constables, Senior Constables, Sergeants, & Senior Sergeants, & possibly plain-clothes Detectives from the Victorian Police Force. They'd be wearing their regulation uniform & carrying a regulation revolver & hand cuffs. The AFP *may* be liaising, but they're Detectives, too. No high-power weapons; no helicopters.
Other mistake: In the fight scene where Bohdi helps special agent Utah you see that his surf board gets broken in two and then after the fight he is seen leaving without the board, but in the scene where he and Tyler are woken up early to go surf right before Tyler says "you look like you just saw a ghost" you see him carrying the same board.
Continuity mistake: As well as the afore mentioned blonde/black hair on the computer screen we also see green eyes on the screen but Angelo reads out 'blue eyes'.
Continuity mistake: During the scene where Utah is chasing the ex-president, we see Ronald Reagan run out of a house and scale a fence into a neighbours garden, instead of running down the driveway. The next shot then shows Utah running out of the house with the fence coming into view, but without seeing the ex-president, and then give chase over the fence. He wouldn't have known to jump over the fence, because he wouldn't have seen him go over it.
Other mistake: When the guy shoots himself in the foot, there is a close up of the gun as it fires. If you watch it carefully you can see that when the gun fires it's pointing outwards, not at the guy's foot. More obvious in slow motion but not necessary.
Continuity mistake: In the night surfing scene, as Johnny gets up for the first wave, he is riding regular (left foot forward), but as the camera cuts back and forth he jumps back and forth between this stance and goofy (right foot forward). All other surfing shots of Johnny in the movie show him surfing goofy.