Other mistake: The television that Lau used to communicate with the crime lords was a regular set carried in by Lau's operatives and placed on the table (which didn't have a mic or camera on it), and there were no cameras in the room. So how was Lau able to see/hear/interact with the crime lords? (00:23:10)
Plot hole: The Nomex survival suit that Bruce gets from Lucius Fox in Batman Begins is bulletproof, knife proof, and can stop anything but a straight-shot, per Fox. All Bruce did was spray paint over it to make the batsuit. But in the beginning of The Dark Knight, Batman gets mauled by a dog which chews through the suit and cuts Bruce's arm, causing him to need stitches.
Trivia: A subtle but very significant tidbit when the Joker is tempting Harvey Dent into shooting him at the hospital: if you look closely at how he (the Joker) has his hands around the gun you'll notice he's actually holding the hammer back, meaning even if Harvey had tried to kill him the gun wouldn't be able to fire. Might first seem a bit hypocritical of the one who talks a great deal about chaos and the fairness thereof, but it actually ties nicely in with the Joker's whole character: he's showing Dent that choice is an illusion, because in this case there isn't one.