he literally goes on boasting about his intricate plan to his enemy like we see in some movies where the villains before their success talk straightly about their evil schemes. Like WTF man?
And the reason is quite the same: Exposition. The cliche villain infodump and Orion's bragging cover the same need a movie sometimes have to explain a plot twist. In the case of the villain, the movie need to connect a few dots of what the hero found out so far, while in the case of Orion it is needed because or the ring structure of that sequence.
Ring because it is a non linear narration that start to a certain point, near the epilogue and then goes back to what happened before to arrive at that point and then move on.
Now, i think it was just brilliant. The ring structure is there as a red herring to make us think the heist went horribly wrong. The cigar dude also clearly say it was comically bad concieved and executed. If the narration was linear we would have just assumed that the heist was going to be a success, so we would have followed who did what in a kinda boring way. With the ring, we had this information: the heist failed. And we were curious and invested in finding out what went wrong and with what conseguences. But then there come the twist: the heist is still ongoing and full on track. And to quick deliver this information Orion had to do exposition and the author had to tell and no show, which is sometimes acceptable.
Now i'm not a literature critic, so i can't tell how well delivered this approach was, but i enjoyed it a lot and i'm not the only one so i guess it wasn't bad after all.
Again, i'm very curious about Caridbis background. The guy REALLY can write and he's an hell of a director.