Continuity mistake: When Alicia is cleaning up Nick's vomit, she removes her gloves. When the angle changes, she starts removing them again. (00:24:45)
Continuity mistake: When Althea and the MRAP first appear in the show, we learn that it has a kill switch that is disengaged by using various switches in the correct order. However, later in the show the MRAP is stolen several times by various different characters. There's no way these characters would've known the procedure to bypass the kill switch, and given how obsessed and protective Althea was over the MRAP, it's extremely unlikely that she kept the start up procedure written down somewhere inside it.
Character mistake: After Nick kills Calvin, and Travis arrives, Nick calls Travis "Nick" before correctly calling him Travis in his next line of dialogue.
Suggested correction: Travis is the one who says "Nick".
Continuity mistake: Althea is missing her right shoe from an earlier scene. When the woman from the helicopter (Isabelle) threatens to break Al's leg, Al is wearing both shoes during the full scene. Next scene, Al is missing her right shoe again. (00:09:45 - 00:10:17)
Continuity mistake: The knife that Nick stabs into the balcony keeps moving between shots.
Audio problem: In the house as the walker is shot nearly point blank, the sound of the shotgun goes off before the flash.
This Land Is Your Land - S3-E13
Other mistake: When Nick is talking to Troy about saving the people on the ranch from the herd, Frank Dillane's British accent slips through. He says "if they do die, it's not because they were too good for this world it's because we failed."