During the Cheese Rolling Contest at the point where Liv speaks directly to the Camera, her hair has mysteriously grown back, even though she cut it off whilst it had been stuck in the Meat Grinder, messing it up.
Liv and Maddie say they won the Chetter-Brat Fest Cheese Rolling Contest together when they were 12, but Liv was in LA at the time.
Diggie never really explained why he didn't choose not to sign up after all when Maddie had her injury, since he'd been in that episode where it happened.