interpretation for this quote?

Question

"Watching him, the boy remarked the absolutely undeviating course which his father held and saw the stiff foot come squarely down in a pile of fresh droppings where a horse had stood in the drive and which his father could have avoided by a simple change of stride." Sorry, I just don't understand how to do this, and I put the quote here because it didn't fit. Thanks

Answer 1

The explanatory phrase is "absolutely undeviating course."

The father would not change course even if it took him through horse droppings.

This also allude to the father's attitude towards life.

Answer 2

It appears that the old man wasn't watching where he was going, and now he has horse feces on his shoe. This situation stinks.