Batman Returns (1992) - 3 questions

Question: Is the fact that the penguins that pull Oswald Cobblepot to his watery grave are obviously not real penguins count as a mistake? They blend well into the background throughout the course of the movie up until this point where it is blatantly obvious.

Answer: Unless you can pinpoint something that proves they are not real penguins (exposed seams, zippers on the costumes, etc) it is not a mistake. They were indeed portrayed by 'little people' in penguin costumes, but to say that they 'just don't look real enough' would be an opinion, not a mistake.

Question: Why exactly does Penguin die? He just falls into his "moat" and comes out bleeding and dying. He wasn't hurt by the bats too much. He made reference to there being a "toxic" lagoon earlier in the movie, so are we to assume the water is polluted by toxic chemicals? And if so, how can the penguins swim in it without being hurt?

Answer: The Penguin dies because he must have a cold environment to survive. At the end of the movie, his lair is in flames and Catwoman has blown up his air conditioner. He overheats and chokes to death. He's also no doubt sufferered injuries because of the rocket bombardment.

Question: Maybe I missed something, but how exactly can The Penguin frame Max Shreck with the toxic waste and documents? In my opinion, I think that Gotham feared Penguin and would dismiss any evidence he had against Shreck. If someone could please enlighten me, I would be thankful.

Answer: If the evidence is convincing enough, the Gotham authorities would believe it, regardless of the source.