Perhaps. But is it also possible that Thomas simply broke under the hardships of his life? Consider his trajectory:
Thomas grew up fatherless on the frontier. He felt an enormous obligation to support his widowed mother and worked from his boyhood to assist her and to develop various businesses, including a store that served both settlers and Cherokees.
Thomas became a great friend of the Cherokee and was eventually adopted into their tribe. His unsuccessful efforts to fight the Cherokee Removal in the late 1830s must have broken some of his spirit. (To this day, some Cherokee refuse to carry a $20 bill with its picture of a fierce Andrew Jackson—the man who defied the Supreme Court, thwarted the efforts of men like Davy Crocket and Will Thomas to help the Cherokee and shipped the Cherokee and other Native Americans west).
In his late 50s, Thomas served through the hardships of the Civil War in Western North Carolina. Once again, as with the Cherokee cause, he suffered defeat. This defeat cost him the fortune that he had built up over a lifetime. Slandered, hounded by creditors and sometimes cheated, he was a broken man financially by the end of his life.
To have watched the destruction of his Cherokee friends, to have witnessed the chaos brought to his beloved mountains by war and invasion and to have lost the work of a lifetime by the end of that war: Surely the stress of these events took their toll on his health and sanity.
— By Jeff Minick • Courtesy of Smoky Mountain Living