Continuity mistake: The tree creature pulls Mace's right hand and arm into the tree. Later, after giving Cindel the medicine, an Ewok examines the wound, which has switched to his left hand.
Continuity mistake: The ferret present during the scene where Wicket and Cindel talk about star cruisers disappears between shots. This is most noticeable when Mace walks in and begins talking to Cindel.
Continuity mistake: When Mace climbs into the cage, Catarine's head keeps changing position between immediate shots.
Continuity mistake: When Mace says "How are we going to get my parents down", he turns his head downwards towards the Ewoks. In the next shot his head is now facing upwards looking towards the cage and not at the Ewoks.
Continuity mistake: The blade on Wicket's knife goes from thick to thin throughout the entire scene he's being attacked by the spider.
Suggested correction: This isn't a mistake. That's him, under the water in the same pose he was in before he touched the water.
After watching the scene, the mistake is valid. When he's underwater, he's not in the same "pose." That would require him to be upside down and squatting. But that's not the pose we see him in.
Bishop73
We see Mace semi-kneeling and reaching out to touch the water when he vanishes, but his upside-down reflection is still in the exact same calm position even when he's gone, and in the next shot we see Mace under the water right-side up, with his arms reaching up to the surface. This is a valid mistake, the suggested correction is not right.
Super Grover