Len Eagleburger wrote the history of the 10th Missouri, Bowen's unit and included a breif note on the shooting. Cornyn may have been involved in a court martial relating to the poor performance of the 1st Alabama Cav USA, one of his units at Bear Creek in May 1863.

http://www.10thmissouricavalry.com/
http://www.1stalabamacavalryusv.com/

John R.