Did the Joker Really Die?

SPOILERS

At the end of Batman Arkham City you will come to a amazing ending to the one of Batmans greatest foes. You would think that joker would be a dumb clown but when he pulls off greatest trick on the world greatest detective. You will find out how much you underestimated his powers. Turns out that the Joker that you thought you new was really just clayface getting the "Role of a lifetime". Clayface made it seem that the Joker was never sick and would transform into a healthy Joker.

Now Did the Joker Really Die?
Here are some intereting reasons to make you might think oherwise.

1. After the game during regular gameplay you can over here some thugs say 'hey if there was two Jokers how do we know that there is not a third"

2. During the Harley Quinns Revenge DLC You also here some thugs talking and one of them ask 'hey how do we know that it wasnt clayface that Batman carried out the theater that night.'

3. During the Final cutscene of the game Joker is standing on top of something eletrical and batman throws his sword at the Joker knocks it down and knocking clayface into the lazurus pit. Batman had had the cure in his left hand then an explosin happens and batman blacks out. He later wakes up and finds the the cure is in his right hand and looks at it wondering. My theory is that Joker Quickly got the cure put it back in the wrong hand of batman and made it sound like he was about to die and needed and then faked his death.