N-Mom, Grandma, and E-Dad... Am I overreacting?

I posted about this a while back, but have been wondering whether or not this was as drastic as the reactions of myself and others merited... If so, it's genuinely disturbing to me and I'm thinking that maybe I wrote it off as an overreaction before because I didn't want to believe it was as bad as it was. But at the same time, I may just not understand something about the situation and it may be normal protocol (even though it's unpleasant).

My E-dad's mom was the best person in the entire world. She was the only one besides her husband who could keep my mom's "personality issues" in check. My dad's sisters have both said that my grandparents knew how my mom was before she even married my dad. They were aware of it, too, but it wasn't until my grandparents passed away that everyone saw the real extent of it.

My dad is a physician, and a damn good one at that. Because of that, he was assigned to be in charge of my grandparents' medical care/decisions after they were incapable of making them personally. My grandpa died quickly after having a major stroke in his sleep, so my dad never really had to make any hard decisions with him. My grandma, however, had a severe and aggressive combination of degenerative diseases along with Parkinson's. She eventually declined to the point where she lost her ability to swallow, and my dad decided that there was no reason to give her a feeding tube since it would just extend her suffering. That argument seemed fair enough... but right before my original post about this, one of his sisters told me something horrifying.

My dad, who loved his mother to death and has practiced medicine for years, told the hospice workers to not come check on my grandma in her last few days. He called in her vitals and such, but for some reason refused to let anyone give her morphine. My aunt said she begged him to give her something to make the pain go away, but he insisted that she wasn't in any pain. She kept telling him that it couldn't hurt to give her some just in case, but he never waivered. They didn't give her a feeding tube or anything, like I said, so she spent a week before her death without food or water. On one hand, I can see where (in his almost neurotic state after years with my N-mom) he would be terrified of making the choice to give her morphine in the off chance that it would be what ultimately killed her. But on the other, she got to where she couldn't even blink because she was so dehydrated. Then comes my N-mom, who apparently opened up the blinds and turned my grandma's head towards it so "she could see outside." This was after she couldn't even blink, much less move her head away from the sunlight if she needed to. My aunt stepped in, obviously horrified.. But my N-mom blew her off and still tried to "take care" of my grandma.

What's everyone's reaction to this? Is this a normal thing that goes on, or is this as horrible as everyone originally said? I'm torn between reluctantly seeing my N-mom/E-dad's viewpoint (ridiculously, but that's what happens when they raise you to never argue with them) and being in absolute disbelief that this happened. What would it have hurt to give her morphine, even if she "wasn't in any pain" like my dad insisted? Maybe someone with a medical background would be able to shed light on the logic behind him saying that. Anything helps though.