Murderbot's face gives nothing away, until that last sentence, and then it grimaces. It's an ugly, pained grimace, one that's at least part wince.

Because it cut itself out of the lives of the only humans it can remember caring about it, as surely as if by death, when it ran away from them. It removed itself from their lives by choice, and without much of a goodbye (okay, yes, Mensah got a novella worth of justification for its choice, but that wasn't enough, that can't have been enough for its favorite human).

"The people on this ship are sentimental. They would care. A lot."