In the article they theorize that he might have been considered a plague spreader. A burial would be a much better way to contain further spread compared to many of the other alternatives (though one might wonder why they didn't just burn the body).
Getting into wild speculation, one interpretation of the "Miasma Theory" could go like this: "Diseases comes from bad vapours. Very nasty disease is in this body. Therefore if we burn this body, miasmic smoke could come out of it."