In the beginning of season 3, Telamericorp changes office buildings. During the flashback the newer office is shown instead of the original one.
When George gets out of his toilet box, Bill is using one of the urinal but he's not sceen entering the public washroom.
In season 3 Episode 10, named Flashback in the day, Alice and Waymond are seen at the college Anders, Blake, Adam and Jillian are frequenting. They are there to recruit. Alice doesn't have braces, yet she have in TAC in the Day.