My analogy wasn't exactly accurate. In order to be more in line with the OP's scenario, my property would have to be a vacant lot across town, the kid would be kicking the soccer ball around at his friend's house beside this vacant lot, and the cops would have been called by a guest of a neighbour who for some reason doesn't like kids playing soccer anywhere near this vacant lot.
You're right, we only have the OP's side of the story, but assuming he's telling the truth about everything the whole scenario is absolutely ridiculous.
I wouldn't dream of making an issue over someone taking a few steps onto my property to retrieve a downed deer. Yes, I suppose if I'd previously had to warn someone a few times about property lines then I might have a problem with it, but there's nothing in the OP's story to suggest that he's had any other issues than a vindictive jealous hunter on another property.