When Godzilla leaves the Roman Colosseum, he knocks down and destroys a large section of its outer walls. When Godzilla returns to the Colosseum later, its walls are intact again.
In the trailer, one of the camel riders around the area where Kong is coming from beneath the ground, begins to run away from the site of Kong's emergence. Shortly thereafter, as it appears it is about to fall into the hole created the camel actually gradually fades out of existence over a couple of seconds. This can be observed in both the trailer, and the final cut of the film available in theaters.
Skar King's eyes are shown to be blue especially in the scene when they show a closeup of his face when he's in his throne room in his introduction, but near the end when he arrives in Rio de Janeiro his eyes are shown to be red or orange.
Trapper assures Dr. Andrews that Kong's new tooth will hold because it's made from the same composite as the heat shields on the vehicles. Heat shielding is notoriously fragile, which is what led to the Columbia space shuttle disaster.
When arriving at the outpost in hollow earth is clearly hinted that a bigger ape (Skar King) did the destruction, however, not much later it is said that Skar king and all the other apes have been trapped in the under-secret realm and can't go out since Kong hasn't found him nor showed him the way out. So surely, is not possible that he destroy the outpost in the first place.
The humans gasp in awe and terror when they see the remains of outpost 1. 'Did Kong do this?' one of them asks. 'No, it's something much bigger'.
Yet when Kong comes face to face with Skar King not too long after, Kong is slightly bigger than him if anything.