The message above:
"Posted By: Gay Mathis
Date: Saturday, 26 January 2008, at 7:26 p.m."
explains there was a newspaper report of that 1902 shooting at the time, so it is not a rumor.
That land dispute and shooting incident is not the type of thing one reads in County History books, which are printed from information contributed by the local families. Have you checked the court records of the land dispute that preceeded the shooting?

If you believe Bloody Bill was cold blooded enough to desert his new bride and younger siblings that he was in charge of after his parents deaths, including the sister who was crippled in the building collapse that killed another sister, and move alone to Brown County in 1864, why would you not believe he shot a man there?
Fran Bolton