During the Arlong Park arc, specifically episodes 33 and 34, Nami stabs her left hand to help Usopp fake his death before the fishmen. Following the incident, Nami wears a glove on her right hand. Then Usopp resurfaces (pun very much intended) and the crew learns that Usopp is not dead. We then see the glove on her left hand to cover the stab wound.
Did I just miswatch the episodes or did the animators screw up?