When Shirley is talking to Max at the open casket, her right hand goes from being on and off his left arm between shots.
Theo is not wearing her gloves when she and Shirley's husband attempt to convince Shirley not to be the one who conducts Nell's embalming. This is especially odd because Theo has a cup of coffee in her hands, which she presumably got from Shirley's kitchen and would therefore be reticent to touching.
One of the flashback scenes show a plush version of Duffy the Disney Bear on a sofa behind Shirley. Duffy would not have existed until 2002.
Elizabeth Reaser looks directly into camera in between 14:00-15:00 minute mark.
The pyjamas Shirley wore in one of the flashbacks was an American Girl brand outfit, specifically the one made to tie in with the Maryellen doll. Maryellen and her collection wouldn't be introduced until 2015.
Hugh says "It's been a minute since one of your color storms" to Olivia. This usage of "it's been a minute" didn't enter the vernacular until the late '00s.
The intake worker at the rehab says she needs a UA and explains that it is a urine analysis. The correct way to say it would be urinalysis, all one word, not two words.
It is very unprofessional of the staff at Luke's rehab facility to be making joking references to the likelihood that rehab will not be successful in the long-run and to assume that Luke is a returning patient. This is especially egregious given how opulent the facility is. The staff would likely be at the top of their field and want to see patients succeed.