There is not necessarily anything terribly exciting in the first chapter yet it totally throws the reader of the trail of what is to come. As soon as the second chapter started in on the life of Gonzo and his new friend I thought "Well, this is nice. Gonzo must surely be important and we're going to get to know how they met and what is so important about him." Then as chapter after chapter goes on Harkaway is constantly throwing it out there for us to see with story after story of these two great friends who have been so tight for so long and so on.

I think by the time we get back to the fire we're ready for the story to pick back up but wait! There's like another two hundred pages left! Then the return to town and the stuff with Leah goes down and Gonzo shoots him and throws him out of the truck and it's like wtf???

I don't think the story would have worked if done chronologically without giving us something to chew on in the back of our minds while the back story was told. I think it worked well or at least served its purpose sufficiently. If we had started out with the second chapter instead after about a hundred pages I personally would have been wondering what the point of continuing on would be.