Burt mentions that there has never been graboid activity in the Southern Hemisphere, and that the events from this movie are the first time they've ever happened south of the equator. The third film opened with Burt dealing with a shrieker horde in Argentina, and the TV show has additionally mentioned graboid sightings in Australia and the Namibian Desert.
During the shootout in the kitchen, the Colt 1911 fires and then clicks three times when empty - this firearm can't do that; for single action semi-automatic pistols, the sound would be made once when the magazine is empty as the hammer fell onto the empty chamber, but with no slide recoil to draw the hammer back, the sound would not be repeated.
When Burt is firing the machine gun he received from the vet in the compound you can see him shaking the gun for/aft as if it was recoiling, however you can also see the bolt is not moving and there are no empty cases coming out.
When Van Wyk is running away from a graboid hauling the cooler containing an egg, first his left arm is in a sling, then in the following scenes his right arm is in the sling.
At 36:39 when the monster flies away taking Thaba, the Moon is smaller than first quarter moon in early night. After a few minutes of movie time line, at 39:13 when Grummer kills the monster with the sword at the bridge, it is bigger than fourth quarter moon, either is opposite side of sky if that was early night, or early morning if that was the same side of sky. More than a fortnight passed within a few minutes.
When Nandi hands the rifle to Burt, he excitedly proclaims that it has a "full banana clip," referring to the magazine. Burt would know the difference between a mag and a clip and would not make that mistake.