When Ellie is attempting to get a better look at the Showground, she runs up to and grasps a Rural Fire Service tanker. The doors to the crew space are closed. In the next part, when she crawls underneath, the camera pans up and the doors are now open.
When Ellie, corrie and Kevin are attempting to get a better look at the Showground, just before Ellie runs up to the fire truck, they all lean up against a blue Suzuki the number plate on said car is CR 22 xx it goes from clean to dirty in half a second.
Numerous examples of vehicles exploding when a bullet hits the fuel tank. Contrary to popular belief, liquid fuel is not explosive, it isn't even flammable. What explodes is vaporized fuel - and then, only if mixed with air in a precise ratio.
The invaders round up the entire population. No real-life invaders have ever done that: it would destroy the value of the invaded society and create immense problems feeding and guarding them. Even the Nazis did deportations by stages.
During the garbage truck chase, many lights can be seen on in the windows of numerous businesses lining the streets, as well as various illuminated signs in the background of several shots, despite the fact that the power is supposed to be out in town, and that most of the invasion took place during the day when no lights would be on.
The helicopter hovering above the home is a Robinson R44, being a small 4 seat, single piston engine helicopter. A military force would never use this type of helicopter for any purpose. The sound effects are that of a larger turbine engine helicopter (which helicopter is difficult to judge as the sound has been modified) and do not match the R44 piston engine.