I mean i dont think they are "trained" to pick up ammo off a range, they are just told to do it some circumstances. i doubt anyone will be noticing where the cases are going shooting back at somone shooting at themselves or be scrambling while getting shot at to get them*. I also dont think you are "trained" to return them, you might return a weapon post disarm or you might have to be told to return it. (plus then you can easily rectify that by having the person who just lost it, get it back by doing a disarm) So even if it was a problem, its easy to fix.
*Maybe the instruction team is trained to pick them up post range use after the unit using it has left.
Apologies orginally was itnented to support your claim but turned into a rant and a worthy response to quote the roginal post.
@Earl Weiss