Welcome to the Family Part 2 - S2-E25
Revealing mistake: When the family releases Chloe's bubble ability for the last time in the episode the bubble machine is visible.
Suggested correction: There is no bubble machine visible.
Thunder Van - S2-E1
Revealing mistake: When Max has the Thunder Van manual, Phoebe uses her telekinesis to get it back. The wires attached to the book are in the shot.
Revealing mistake: The stunt double for Bradford is rather obvious when he's in his wrestling uniform.
Revealing mistake: When the Venus Fly Trap is shrinking back to normal, the wires holding it up can be seen.
Revealing mistake: When Max pushes the stroller into his house, look into the stroller and you can see a baby doll, not a real baby.
Revealing mistake: When Phoebe freezes the secretary, you can see that she is frozen before Phoebe's "freeze breath" gets to her.
Welcome to the Family Part 1 - S2-E24
Revealing mistake: When the father is launched down the stairs he's very obviously been replaced by a dummy. Watch how his left arm bends awkwardly.
Revealing mistake: When the whip is sparking, no black marks are left on the floor.
Revealing mistake: When Max is strapped to the armchair it becomes obvious on at least three occasions throughout the scene that the strap is not secure and he can escape the chair by pressing down into the fabric, but chooses not to.