Ask what got in the way before deciding someone did not care enough.

Attributing behavior to character is quick and usually wrong. When something does not arrive, the mind reaches for a story about how much the person cares, while the common explanations are duller: illness, a message never seen, another crisis, a week that disappeared. Getting the story wrong costs twice, since you also lose the chance to fix whatever actually happened.

Ask what got in the way, plainly and without an edge in your voice, before you decide anything. Leave room for an answer that is not impressive. Most people are managing more than you can see from where you stand.