So just finished Season 5. Without getting into spoilers, while I still love the series, I didn't think Season 5 was as good as previous seasons. Some great scenes certainly. One of the things that bugged me though is they seemed to be sending Walt off the deep end a bit. I'm almost feeling sympathy for Nighthorse.
Longmire is already a flawed hero - we see that in Season 1, episode 1. No reason to turn him into a lunatic. Maybe the next to last scene in episode 10 with the smarmy lawyer will snap Walt out of it. Leave Walt alone, writers.