www.UsingEnglish.com provides this explanation: "If you shoot yourself in the foot, you do something that damages your ambition, career, etc."
The newspaper article didn't describe in what room of Beatty's home the shooting took place. Was he changing clothes or in the bathroom? In any event, the gun fell out of his pants pocket, hit the floor and Bang! Beatty took a round in his left foot.
Hebron's officer (more than one?) was dispatched to his home, and somehow the McHenry County Sheriff's Department got involved. This led to a media statement by the Undersheriff, who must be looking for all the face time he can get in the press. Why didn't the Hebron P.D. just issue the press release?
Zinke's statement about the evidence, trajectory, angle and bullet recovery about the one-shot self-inflicted injury is more than was said by the McHenry County Sheriff's Department in 260-plus pages of reports after the triple homicide near Marengo a year ago, when Jack and Audrey Feldkamp and doran Bloom died.