Humane?

There is an almost unbearable article in the New York Times about a woman tying desperately to get appropriate care for her elderly father so that he can die at home, as was his wish.
The story resonates too closely and too painfully for me to even discuss right now, too many details are familiar, but this horrified me:

A doctor said withholding liquids [from her aging mother] was “the humane way." Once, arriving for her daily visit, [the daughter] had unthinkingly carried in a cup of tea. Not quickly enough, she hid it behind a curtain, seeing her mother pass her tongue over parched lips. “She was suffering, and I contributed to that,” she said, sobbing. “I will never forgive myself. 

Okay.
I know that it is arguable that a point may come when a conscious dying person refuses food or hydration and so to not withhold it would be inhumane.
And alternatively, it is possible that if a person is dying and no longer sentient there is no cruelty in depriving her of liquids.

But how in the name of God and all that's holy can it be "humane" to allow someone who feels thirst and visibly suffers from that thirst to die of thirst?