You do not write a rationing schedule in careful handwriting by accident, in a moment of frustration.

You write it deliberately, at a table, with time and thought, the way you would design any other system meant to produce a reliable result.

My wife had not neglected my mother.

She had project-managed her.

She had approached the breaking of an old woman with the same organized, methodical, detail-oriented care that a decent person brings to protecting one, and had simply aimed all of that care in the direction of cruelty.

That is a specific kind of evil, the kind that requires planning and patience of its own, and it does not come from a bad moment or a lost temper.