In the scenes where pregnant "Joy" is in the shower, the body double is wearing flesh colored panties, just barely visible at the bottom of the screen. This goof is likely not visible on CRT televisions that over-scan.
When Joy is shown counterfeiting 20's in 1996, they are the bills that were redesigned in 2004.
In the series, it is established that Darnell "Crabman" Turner was once a Canadian immigrant named Harry Monroe and was placed into the Witness Protection Program by the FBI and moved to Camden to start his new life. However, in the Season 2 episode "Our 'COPS' is on" which flashes back to Earl's criminal days and when he was still married to Joy, Darnell is living with his grandmother in Camden and is caught by the police growing marijuana in her apartment.