Factual error: They used an EpiPen to bring Liv back but they're holding it backwards. The way it's being held, Ravi would have injected himself instead of Liv and she wouldn't be revived.
Continuity mistake: Ravi initially speaks about having previous assistants in the morgue; However Ravi was working for the CDC at the time of the boat massacre before authoring his zombie paper. Meaning that Ravi and Liv must have started working at the morgue within a week of each other, which completely destroys the establishing dialogue of Ravi working in the morgue for a long time.
Continuity mistake: When Vaughn's assistant puts down the newspaper in front of him, it switches position to the left between shots. (00:38:20)
Continuity mistake: In the parking garage, when they review Regina getting shot, a bullet wound can be seen on her back before the gun is fired. (00:37:12)
Continuity mistake: The way Regina is lying after being shot dead changes when Ravi and Liv are there, her arms are positioned differently and the body moves relative to the lines on the concrete floor. The knife is positioned differently too.
Other mistake: When Liv is pretending to be Major and texting Rita at the end of the episode, the text messages appear on the wrong side. Rita's messages should be on the left and Major's replies should be on the right.
Return of the Dead Guy - S3-E10
Continuity mistake: When Ravi is bitten on the top right side of his head by Don E, there is a noticeable hole in the pantyhose he is wearing to disguise himself. Just a few seconds later, they show the right side of his head again and the hole has disappeared. (00:28:20)
Don't Hate the Player, Hate the Brain - S4-E7
Other mistake: When you see the Brother Love pamphlet Liv is reading, after verses 1-5, it goes back to 1 and repeats the same 5 verses before continuing on with verse 6.
Insane in the Germ Brain - S4-E11
Revealing mistake: Near the end of the episode, a zombie hating teenager barges into the church to assassinate brother love. He ends up shooting a choir member instead. Although the gun goes off, blood splatters as if it were a head shot, and the man collapses, there is no point of entry. They forgot to CGI the headshot.
All's Well That Ends Well - S5-E13
Plot hole: How can Peyton eat the brain of the girl in the wedding dress if her brain was sold as a zombie cure?