It helps that the screenwriter wrote some of my favorite Westerns, and it seems like he was motivated to do an honest depiction of Hamer:
When 86-year-old Frank Jr. arrived, he had an escort comprised of his son Frank III and several nephews and relatives. Frank, himself, had a heavy bandage on his right elbow, covering an infected water moccasin bite. He wore suspenders, a Texas Longhorns ball cap, outsized sunglasses, and he was packing a sidearm at his rear waistband. We all sat in an empty Austin steakhouse at 11 am, at a dark back table, sipping shots of bourbon. After my introduction and explaining why I was there and what my mission was in terms of giving Frank Hamer his due, Frank Jr. stared across the table and said, “I’m still fixin’ to hunt up that Warren Beatty and put a bullet in the sonuvabitch.”I'm so stoked.
Turns out that there might be another reason to get a Netflix subscription...