Kong could have grabbed Jack
In the tree crossing scene, Jack hides in a shallow cave. Kong tries to grab him but we are supposed to believe Jack is out of his reach. Not believable! Kong’s hand is totally within reach of Jack.
They should have
(1) made the cave deeper, but then the lighting would be challenging, or
(2) made the cave lower and more out of reach, but then the shot is trickier to frame, or
(3) put an obstacle like a jagged rock ledge or tree branch as a barrier at the cave’s entrance. Bingo!