The fate awaiting Abner Snopes at the end of "Barn Burning" is uncertain, but it is definitely not very optimistic. His son is of course successful in alterting Major de Spain before Abner manages to really get the fire going, and therefore he manages to avert significant damage. However, the fact is that Abner would still have been caught red handed in the act of trying to set fire to the barn. This, given his previous history and the harshness of laws at the time would indicate that at best he could hope for a spell in prison, and at worse he could expect to be hung. The text makes it clear that Abner Snopes is a self-serving individual who cares only for his own sense of pride. He has built his identity upon an illusion, and this illusion has been believed by even his son, as the following quote makes clear. Note what Sarty says when he runs away from the barn and away from his father forever:
"He was brave!" he cried suddenly, aloud but not loud, no more than a whisper: "He was! He was in the war!! He was in Colonel Sartoris' cav'ry!" not knowing thathis father had gone to that war a private in the fine old European sense, wearing no uniform, admitting the authority of and giving fidelity to no man or army or flag, going to war as Malbrouck himself did: for booty...
The true Abner Snopes is therefore painted by the narrator as a selfish individual, and the fate that awaits him after the end of the story as he is caught in the act of setting fire to the barn of Major de Spain is not hopeful. However, given his character, it also could be seen as inevitable sooner or later. Upon reflection, Abner is lucky to have escaped punishment for his various crimes for as long as he has.