The group with the two cannons on a raft is shown going by the same place on the river twice.
The chalk marking Harold makes for the spare in bowling changes from when it is initially made (at around 35 mins) and when seen the second time (at around 54 mins) to when the same door is seen about a 1½ minutes later. When Colosso comes back through the door when Harold's Nurse is there, the mark is as it was originally.
Although the film is supposed to be set on a tropical island, the characters all wear Mexican garb except for Harold van Pelham, and the setting looks like a Mexican village. This is because the film was originally set in Mexico, but legal issues forced Harold Lloyd to change the setting to Paradiso.
When Harold shoots the cannon on Colosso's back at the raft on the river, a bag containing the explosives hanging on a wire across the river is briefly visible before it detonates. In a following shot, the bag containing explosives on the side of the bridge deck is also briefly visible before it goes off. Still later, the same scenario occurs when Harold accidentally shoots the hen-house with Pipps inside - the bag is visible above the ground with a wire running from it off to the right. Wires are also visible that are attached to the hen-house to pull it apart when the explosion happens.