When Tarzan throws the hunter over the cliff at the end, the hunter's body makes a big splash when it hits the water as seen from below looking up, but then the view switches to the top of the cliff looking down, the hunter's body is on a large flat rock above water level where it could not have caused a splash.
When Dino ties up the boat for the night he very clearly ties the rope to a tree. The next morning when they are getting ready to leave he is carrying the anchor from dry land onto the boat with no trees anywhere near.
When the hunter shoots at Tarzan in the tree and it hits a limb near his hand, the hunter then shoots again in the air without working the bolt action on the rifle to eject the spent shell and load a fresh cartridge.
When Slade goes over the cliff, the metal garrote is tossed to the side but when his body is seen from above it is laying next to Slade.
When the people in the boat throw the first stick of dynamite after being trapped between two fallen trees on the river, only one stick is thrown but several different explosions occur simultaneously.
Although there is never one shown, there must be a barber shop or beauty parlor somewhere in the jungle - Tarzan appears throughout this film with a clean-shaven face and perfectly coiffed hair. The British characters, however, frequently sport "five o'clock shadow."
Although Paramount clearly sent cameras to locations in Africa to capture wide shots, backgrounds and atmospheric material, more than 50% of this film was obviously filmed on a studio back-lot or soundstage - much of it with poorly executed use of rear projection and blue screen techniques.
When the hunter shoots his rifle in the air after narrowly missing Tarzan in the tree, the sound of the shot comes a second or two before the trigger pull and muzzle flash occur.