[Jeritron]

I understand that, but it kinda still eluded my question. How's it "his half" if they never paid him for the job, because he never did it?

Also, the mob does get a chance to be happy because the meeting with the pile of money was pre-arranged. Maroni doesn't go because he tips Gordon off about it, but the Chechen does and thats where he gets killed. Maroni was obviously supposed to be there for the "exchange" or whatever, which is why Joker asks where the italian is.

So what basically happens is, Joker gets all the money from Lao like you said but doesnt specifically complete what they hired him for, but when the Chechen gets there they talk about how Joker lived up to his word. Which makes it quite simple.

A) It was a different outcome, but they were equally happy with The Joker for setting the situation right, and were gonna give him his half.
or
B) The capture of Lao was also a condition of their agreement and they were giving him his half.

or C) The Joker hooked them up bigtime and considered half of the money his to burn.

I'd lean towards it being either B or C

It's really the only peice of the puzzle that is a bit confusing and doesnt' have a concrete answer. It only doesn't have an answer because it's never adressed on screen and several things that transpire indicate different possibilities in that portion of the plot.

It's not a flaw though, because either scenario makes sense. However, theres no way of telling what the deal is