According to Mr. Fitch's research, Exum Artis had nothing to do with the Rebellion. He and his in-law Thomas Haithcock were furious when one of Exum's relatives (a cousin?) was murdered by rampaging whites after the Rebellion. Most free African Americans remained indoors because whites were riding on horseback throughout the county and adjoining counties creating havoc. (I recall seeing a letter from a member of the Roberts family of Northampton County, NC, who wrote how they huddled indoors, fearing for their lives).

However, Artis and Haithcock were so furious over the murder that they lost their tempers and freely expressed their opinions on the matter. That is what landed them in jail, and, if I remember correctly, put Exum on the gallows.
Paul