There are several plot holes surrounding her death. Have you seen patients worse guarded in your whole life? I have never seen a hospital where someone could come into a back entrance and enter someone's room. But the whole point of what he did was to honor her wishes, and show the closing of the relationship. I would guess that many of the jumps made in the plot around this are the fact that FX Toole who wrote it probably didn't know a lot about these situations.
I have. Everybody I've ever visited in the hospital except mothers with new borns (where there's TONS of security) I just walked in through a convenient entrance and went to their room, only time I ever talked to an employee was when they were doing something with the patient while I was there or I specifically sought them out for some reason (find out what room I was aiming for, discuss the actual medical situation).