When Prue (the dog) is chasing the Banshee away from the teenager. You see the Banshee running from the scene bare foot. The Banshee jumps from the ground onto a car, she is wearing sneakers. As she jumps from the car back to the ground, she's bare foot again.
When Piper is yelling at Prue (the dog) her hair switch's sides between shots
About 33 minutes into the show, Phoebe is wearing a gray sweatshirt with a flowery shirt on underneath. During the next minute, her sweatshirt is seen zipped and then unzipped repeatedly.
When Phoebe is writing in the book of shadows about Cole's Human Form she is seen moving her hand very quickly over the book. On a closer shot you can see she is not writing, just pretending to holding the pen above the paper.
Banshee Phoebe and Belthazor fight in the mausoleum, and Phoebe knocks Belthazor over a tomb. When he falls his legs come into view and his pants legs come up a bit revealing his very human colored legs.
When Prue (a female dog) is chasing Kit she stops at the stairwell where Piper is. In this scene Prue has a crotch.