At the end of Chapter 10, it is ironic that the narrator discovers the owner of the Spotted Dog. Why?

The narrator was looking for the owner of the Spotted Dog to return his cart. Ironically, he finds him dead.

Near the top I stumbled upon something soft, and, by a flash of lightning, saw between my feet a heap of black broadcloth and a pair of boots. Before I could distinguish clearly how the man lay, the flicker of light had passed. I stood over him waiting for the next flash. When it came, I saw that he was a sturdy man, cheaply but not shabbily dressed; his head was bent under his body, and he lay crumpled up close to the fence, as though he had been flung violently against it.

Overcoming the repugnance natural to one who had never before touched a dead body, I stooped and turned him over to feel for his heart. He was quite dead. Apparently his neck had been broken. The lightning flashed for a third time, and his face leaped upon me. I sprang to my feet. It was the landlord of the Spotted Dog, whose conveyance I had taken.