[David Brinza]

"Robots will have to be built robustly to avoid damage from falling Trackballs."
-- 2008 Overdrive Animation.

There are non-shooting robots that can drop a Trackball more than 10' (Team 294: front and center!). An eight pound ball dropped from that height can do some serious damage. Balls dropped from that height can also careen off the field. Safety concerns about the kinetic energy of Trackballs will involve more than shooters.

I think the bigger concern is the risk of the shooter mechanism itself. Teams with shooters need to consider the effects of various failure modes (i.e. suppose this bolt comes loose, what if this bracket gets bent, and so on) and design accordingly. Team members should be prepared to tell the inspectors what fail-safe provisions are included to avoid injury to team members and people NOT familiar with the robot (referees, alliance partners, field reset, etc.). If your robot is a shooter, your "Release Safety Officer" should expect to get grilled on the contents of Update 5. Inspectors will not give much lattitude to a team that hasn't paid attention to safety considerations in their design.