Dina's sexy cop outfit includes thigh-high, high-heeled boots. When she and Jonah cover the corpse in the wall, she's wearing lace-up shoes.
The knife that Kelly pulls from the knife block clearly has a solid blade. It is only after she stabs Jonah with it that it switches to a trick knife with a visible break between the top, retractable part of the blade, and the much wider lower part of the blade.
Sarah wears a goldfish costume for most of the episode, however, in one shot where she'd working the register, she is wearing her turtle costume from the previous season's Halloween Theft (2016). It is possible this was a deleted bit of footage filmed the previous year that was recycled.
When Glenn makes several announcements over the loudspeaker in a row, warning people away from the house wears section (where Sal's dead body is), he doesn't hang up the phone or end the broadcast function in any way. His part of the conversation with Jonah should have been audible over the PA, and when he dialed the buttons to begin another address, the beeping should have been heard over the speaker system.
Sal is said to have been dead for "at least a year." Sal was mentioned in Black Friday (2016), which took place the previous Thanksgiving, only 11 months prior to this episode.