[reliabilityguy]

Because the latter implies some external attribute to it?

[wat10000]

That's what makes the latter more accurate.

[reliabilityguy]

How come?

[wat10000]

Because there often is an external attribute, especially if you consider illness to be “external” as is conventional for most deaths caused by illness.

[reliabilityguy]

Some illnesses are internal though, e.g., various genetic disorders people are born with, or some mental illnesses, etc.