Corrected entry: It's unreasonable to assume that Sarah couldn't have found that PAT's configurations had been changed. Ben had DELETED some of them even, and it would have been a red flag if he had only DISABLED them, so for Sarah to overlook this is only convenient to the plot, and something she easily should have been able to detect.
Corrected entry: The amount of time it takes PAT to produce things in the kitchen is completely unrealistic. The items show up way before they could realistically arrive on the platform once they are requested.
Correction: I've thought this too as this is certainly impossible of modern technology we have today. However, the theme of the house is it's a house of the future. Its capabilities make it amazing because nobody can understand how it's done. I think it's reasonable to assume that this house has technological advances that will only be available some time in the future; and I wouldn't be shocked if there's a point in the future where technology is so advanced that food can be produced in an instant.
Corrected entry: When Angie gets her hand scanned by PAT. PAT is able to tell her age, illnesses, injuries and if she has broken bones. Sara explains it uses a DNA sample for these tests. DNA samples do not hold this kind of information.
Correction: The sample would be used to find her medical history on file with the hospital that has the information.
Correction: Pat had also gained a mind of her own by this point. For all we know, she covered everything Ben did so Sara couldn't change her back.