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.
Abra Cadaver - S2-E7
Continuity mistake: When Peyton and Ravi are talking in the kitchen, there's bananas in the blender that keep changing position through the scene.
Real Dead Housewife of Seattle - S2-E3
Trivia: Liv says to her roommate "a long time ago we used to be friends," talking about her former roommate Peyton who is now back in Seattle. This is a direct homage to the lyrics to the theme song from Veronica Mars (created by Rob Thomas, who also created iZombie).