I'm not a doctor but I suspect he probably had tularemia, not the plague. I know about it because my Dad nearly died from it as a result of hunting and skinning jackrabbits. It's very infectious and can be fatal if not identified quickly.
He initially went in the hospital with really bad flu-like symptoms. Treatment for tularemia and plague are the same, but in his case, it just came too late. If I recall, he died the day after entering the hospital. He was confirmed as a plague case (one of five that year in the US, I think).