There are a couple of points about this "ball" gadget that are being mentioned, but not addressed fully.
"it won't fit in the holster". Obvious, sure. But you can make a holster to fit anything. Whether it would work, or whether the cops would wear & use them, are different questions.
"cops don't have the time to snap this thing on the gun". Again, obvious, and completely true for many situations. There are times when a cop would have the time to attach one though. And, as a counter point, note that cops don't carry rubber bullets, beanbags, etc as their duty ammo.
They only load with the "less likely lethal" rounds when they expect,
in advance they will be more useful than regular ammo.
The only instant choice the cop has is what he draws from what he has with him. Gun, Taser, baton (if he has them) are the usual choices, and that is an apples vs oranges, vs watermelon discussion.
It's a pretty safe bet the ball's designer plays pool. The bullet is the cue stick, sending the cueball across the table (down range). The pool balls are the same hard stuff as the cueball. People, are not.
ENERGY, velocity, surface area. These matter, and I'm sure the designer has done tons of various calculations. So far, I see no mention of the actual force of impact. Got any ideas? Use a 9mm for a cue stick. What force is the ball gonna have at intended range? guesses? would 300ft/lbs seem realistic?
Remember that since the cueball is trapping the bullet, all the bullet's energy is used. Some of it gets the cueball moving (at what speed?) the rest goes downrange with the cueball. (maybe we should call it a "Clueball" ?)
Clearly the intent is the surface area of the clueball spreads the impact energy, and (at the levels involved) prevents penetration of a person. Therefore, it is less likely to be lethal. Good theory, actually works,
less likely,
not nonlethal.
Swing a sword at someone's head, hit them edge on, cuts the head open/off. Result: DRT. Same sword, same swing, same head; hit with the flat of the sword. Caves the head in, (or breaks neck) Result: DRT.
Stab someone COM. Puncture heart/lungs, bleeding, serious risk of death.
Hit them with a baseball bat, No direct penetration from the impacting object, but break rib, rib punctures heart/lung, bleeding, serious risk of death.
OK, not perfect analogies, but the point is the same energy CAN be lethal, from either a point source (sword edge, ice pick, bullet) or a larger impact area (Sword flat, baseball bat, etc.)
I think "clueball" is a good name, because a)if you pop someone with one of these, its a real good clue you aren't happy with what they are doing, and b) because I think the designer doesn't have one!