lpd said:

Anyone considered a civil war within the Empire with a New Order taking control while a Sith led Empire still exists? It could be why we see the chaos in that shot where it looks like troopers are fighting troopers.

I think we're seeing John Boyega's Stormtrooper character fleeing his situation in that TIE Fighter in that scene. For better or worse that scene may harken back to Episode I where young Anakin is learning how to pilot a starfighter on the fly.

I don't think we'll be seeing anything about fighting within the First Order/Empire other than that scene in these sequels.