Audio problem: When Batman types on the computer in Dr. Young's office, the clacking sounds are woefully out of synch with his hand movements, not to mention his fingers never actually touch the keyboard.
Other mistake: While playing as the Joker, despite his claims that he'll kill all enemies he comes across, if you zoom in on their corpses, you'll notice that they're still breathing, regardless of how you take them out (take-down, shot, or blown up). It's easier to spot this mistake in the invisible predator challenge maps.
Trivia: After Dr. Young is killed in the warden's office, go back down the stairs but do not go through the archway. Instead, after going down the steps, turn right and you will come to a blank wall. Spray the explosive gel on the wall three times and then detonate it. The wall will break apart and you will find a secret room. Go inside and you will find blueprints for the Arkham City Prison Complex.
Question: Why would Poison Ivy accept several Titan shots from The Joker? She hates him.