When Cat ran away from Tori, she is seen throwing a water bottle from her hand. However, in the previous shot, she had no water bottle on her hand.
When Beck and Jade are kissing, Jade puts her hand on Beck's head, but when the camera switch, her hand is no longer there and her sweater sleeve is covering her hand.
In TV listings, it says that Cat dates Trina's ex-boyfriend Michael, but she dates Tori's ex-boyfriend Daniel.
When Tori drags Cat into the Janitor's closet, Tori didn't turn the handle and it automatically opened. Tori couldn't have reached it and Tori's hands were on Cat's feet. Response: She let go of Cat's right leg for a second with her left hand, pushed down the door handle with her left hand while keeping a grip on Cat's left leg with her other hand. Then she resumed grabbing Cat's legs with both hands.
When Cat and Tori leave the janitor's closet and shut the door, the hoses attached to the wall shake, revealing it is a prop wall.
When Tori sprays hot cheese on Daniel and Cat, they don't see her do it, but they seem to know she did somehow.
Although exposed to the fish at different times, those who used the fish all ended up showing symptoms at the same time.