When Summer and Slade are arguing during the party, the part in Summer's hair changes sides between shots.
Despite being clearly not present in any other scenes at the party, Newman appears to help lift Clint out of the pool.
In the opening montage of Matt's party a shot is used of C.J. walking up to the beach house. However later there is a completely separate scene of C.J. being admired by beach goers whom give her directions to the party and the exact same shot is reused of C.J. walking up to the beach house.
Throughout Summer's first day of school, the part in her hair alternates between being centered and being more toward her left.