Yes, but is there a god?
All of your solutions to the above question are based on an inherent logic involved in the complex interaction of man, weather, and shovel. All measurable, observable, practical things.
Let's just add a few to point out some absurdities:
*God ordered half of them to stop halfway through.
*An angel came down and took pity on them and finished the job for them in a millisecond.
*They prayed for god to open the earth for them and thus it was granted.
*Satan appeared, laughed, and turned the dirt they were digging into granite.
Etc.
Yes, it is also an example of the fallacies of thinking only inductively, which of course, you missed.
*Adds supe to the list of literal atheists with ltd lateral capacities*
This may actually be a breakthrough... hmm I wonder if anyone would fund a research proposal on estimating the balance of inductive vs abductive reasoning in atheists and theists.