Spoilers
In his speech on the balcony, the younger brother of the victim says that he agreed to the meeting because the producer was nice to him. He seemed very honest and sincere that he was duped into doing it. In other shots the movie tells us that his motive all along was to kill the perpertrator.
Yes he felt duped into meeting her... because she approached him by being nice and breaking the ice and then telling him why she was really meeting him. So he decided to meet AL so that he could kill him. It was only after the runner girl told him that AL was a miserable haunted man that he had second thoughts or just got too scared to kill him. I think that he was just scared because he tried to kill him when he got the chance to meet him again.
shareWas he duped or was he the one who was doing the duping?
He came there to kill. (remember he brought the knife)
I think you guys took the crazed rambling as inconsistency.
You're looking at a man half gone mad, and you want him to be reasonable.