Other mistake: It is established that Drs. Quest and Hartman speak the Po-Ho's language, but when they are captured, Dr. Hartman is translating to Dr. Quest how the Po-Hos are going to torture them.
Other mistake: In this episode, Hera's ears are shown for the first time thanks to her civilian disguise. As for all Twi'lek women, they're shaped like cones. However, they are too large to fit under the ear coverings of the pilot's cap she usually wears, when they've been shown on the few occasions she hasn't been wearing goggles or a pilot's visor.
The Return of Hydro-Man: Part 1 - S5-E7
Other mistake: When Spider-Man catches up to Mary Jane and Hydro-Man at the foundry, he webs up Hydro-Man's left wrist. When the shot changes to Spider-Man landing, he is not holding onto the web-line. When the shot changes back to Hydro-Man, his arm his pulled with the web-line remaining taut, even though Spider-Man is not holding the web. If Hydro-Man was moving his arm on his own, then the web-line would be slack.
Other mistake: The first victim of the mask in the series falls back against crates that must be made of dry leaves, since all it takes is for the body to lean against them to utterly shatter them. (00:18:55)
Other mistake: When Seiya blasts with his special move the helicopter, causes an explosion, but there's no damage on the vehicle nor smoke, fire or any sign of what he has done when we see it spin and eventually crash-land. (00:13:50)