Talking this over with my husband (from a farm family) he has the opinion that a farmer would never come out of his shoes in the field unless they were super muddy and therefore heavy. From the photos it appears this area is dry, dry, dry. Which makes me wonder if the barefoot man either took the boots or was given them, then decided when walking he'd rather be barefoot (they didn't fit well, blisters, etc.) and he pitched them. JMO.
I also agree they need to check that dirt pile unless it's obviously undisturbed.