What's oddly unsaid here is WHY private landowners would care if you pass over their land for a half second without stepping on it. And the obvious answer is that they are treating public lands as their own private game reserve by blocking access.
The more interesting question is why the sheriff is colluding with them to enforce this, since the men were not apparently caught in the act of stepping over the corner. Rather the sheriff is using their state powers to provide security for a wealthy private citizen's misuse of public lands, and using the corner locking as a loophole to treat citizens on public lands as presumed trespassers. That seems like a more interesting story.
The more interesting question is why the sheriff is colluding with them to enforce this, since the men were not apparently caught in the act of stepping over the corner. Rather the sheriff is using their state powers to provide security for a wealthy private citizen's misuse of public lands, and using the corner locking as a loophole to treat citizens on public lands as presumed trespassers. That seems like a more interesting story.