This all kind of reminds me of when Jim Henson (of Muppets fame) died; he had a sore throat for several days (which turned out to be strep), got much sicker suddenly and died less than a day after going to the ER. That was in 1990, but I still remember it well because my doctor told me that with my asthma, I needed a flu shot every year and a pneumonia shot right then; she used Henson as an example of someone who was receiving undoubtedly excellent health care but was still quickly overwhelmed and died once the bacterial pneumonia set in.
I would think athletes would be particularly prone to delaying treatment, if that is what happened here. They've spent most of their lives being told to ignore pain, injuries and sickness and compete anyway.