Plot hole: The girls refer to Holly's owner as Mr Volker, even though they now know her owner is Mr Allbright. For plot reasons, they have to say to Sherry that Mr Volker is Holly's owner, because now she knows she's killed the wrong man, and she'll have to kill again.
Plot hole: The first man to be killed is a psychiatrist - "a very private man". So, if he was "very private", how did the "hip man" know if he did or did not have any psychotic patients who would want to kill him? He wouldn't.
Chosen answer: Maybe she thinks she's so old that she'll be back in the mortuary soon, so why go home?
kh1616