When Carly was watching iGibby, it says that it is live. It can't be live, because Sam, Gibby, and Freddie weren't in the iCarly studio, (Carly was), and in the studio, but not on the website, there were mini golf holes. Response: However, it was just a dream sequence.
Before Carly got sprayed, her shirt was already wet.
At the end of the episode when Spencer comes out of the shower he clearly has shaving cream all over his head, not shampoo.