Character mistake: The registration number of Alan Salt's car is HUA222B, but when Rachel is on the phone asking an officer to look up the car's registered owner she gives the registration number as B222HUA.
Character mistake: Near the end, when Michael reveals to Brennen he knows everything about him, he says, "I know everything about Tyler Brennen." Michael emphasizes "Tyler" as if it's a big deal that he knows Brennen's first name. Michael already knew Brennen's first name from the first time he met him, in Season 2, Episode 15 "Sins of Omission."
Character mistake: Rufus says "That was before I found out you raped my 14 year old daughter." referring to Jenny. Jenny, in previous seasons is 15. Jenny was born in 1993, and season 4 was filmed in 2010, making Jenny 16 at least. (00:25:35)
Suggested correction: In this scene, Rufus saying, "my 14 year old daughter..." was referring to Jenny's age at the time Chuck tired to force himself onto her (beginning of the first season), not her current age in season 4. Jenny was 14 in the beginning of season 1.
Character mistake: Roxy always calls her mother Marda, but in the first episode, she is on the phone with her and she says, "Mom, I gotta go."