It can and will happen however careful you are. Your brass can bounce of the range roof post back at you. Anyone else’s brass can go anywhere. Shots that hit rock or steel can fragment and send pieces your way.
If you RSO a lot of matches it will happen a lot more.
As someone said, the most important thing no matter what is to keep your muzzle downrange and get your finger off the trigger. Brass, wasp sting, siren behind you, snake running over your foot, plane crash, spider drops on you, alien landing, lightning strike nearby, twist your ankle or trip and fall down while shooting, whatever. Muzzle and trigger discipline all the time. Never relax your guard on those. Should always be in forefront of your mind if a gun is in your hand or anyone else’s around you. If you are in that habit for little unexpected things, it will carry through something big unexpected happening.