Do dogs like bringing back balls and sticks because it's really helpful if your spear or sling shot misses the mammoth?
Credit to my fiance with a special interest in evolutionary biology and the history of human domestication of other species (and who is also currently HIGH AS HELL).
Many dogs, including Labradors, were specifically bred to retrieve certain items for their human owners.
I guess precisely what those objects were was not of paramount importance to the author.
But I also found this, which suggests the answer is no:
Whether it was fetching ducks, birds or other game, these dogs knew their job. They were also bred for an attribute known as ‘soft mouth’, a combination of physical traits and attitude that meant they could carry the game without damaging it. If you have a retriever, you’ve probably noticed how gentle they can be during fetch.
"Soft mouth" means they don't bite what they're retrieving. Spears and arrows don't need "soft mouth". Plus a dog can be trained to "point" to something or just run it out. Why waste a spear or an arrow or a bullet when you have a pack of hounds that will run out the coon, fox, etc? Let the dogs do the work - there's no need for a spear when the deer collapses from exhaustion.
I 'm sorta doubting it. I know some dogs have this inherent tendency -like a Labrador. But no doubt they've been selectively bred for that behavior over centuries. We have GSD's that will retrieve as part of their prey drive. They want to chase and catch. They love frisbee. But it's often quite a process to get them to understand the bringing back part. Once they understand it facilitates another chase they will be dependable retrievers. But that sometimes takes a lot of repetition. "No take. Only throw!"