When the widowed ape is holding George (Crosby) in her lap, Crosby's socks switch between red in one shot and pale yellow in the next shot. Skipping back and forth - the scene must have been filmed over more than one day.
When Lala comes ashore after the shipwreck, her dress is torn but reaches to mid-calf or lower. Later when they arrive at the abandoned hut, the dress is now mid-thigh length.
When they are on the island, Lala has no flower in her hair, then flowers at the back of her ponytail and then a big flower on the side of her head - it keeps changing. Also, her skirt is quite long up until the time the crocodile is after Bob Hope in the pond. But in the next scene, her skirt is about thigh-high.
When George and Harold meet Lala, Harold's coat is held on his right shoulder. But, between shots, Harold appears holding the coat in front of himself.
When George, Harold and Lala are chased away from the African Queen by the tiger, Lala has flowers at the back of her hair. When they entered the village in the next shot, the flower display is over Lala's right ear.
Although the ships' wheels are roped to the rudder and affixed to the deck strongly enough to withstand a storm, when their boat hits the rock, the wheel mounting falls to the side, clearly not attached to anything.
In the close-ups of Harold when he's diving for the treasure, there's no glass in the faceplate of the helmet. Clearly, Bob Hope wasn't under water during the scene.
The Captain of the ship says to George and Harold that the ship sails at sunset. The scene showing the ship leaving, its broad daylight.
A man throws a boomerang at Hope and Crosby, Hope catches it then it's seen in the man's hand again.