Plot hole: In the start of season 4 we meet Liberty's little brother, Danny. J.T. and Manny are making fun of him because he is new to the school and is starting out. If he is starting out, then he should be in the 7th grade, because it is stated in the first episode that the school changed into a 7-12. Liberty, J.T., Manny, Emma,Toby etc. are all in the 10th grade so how does it end up that Danny is a grade below Liberty?
Continuity mistake: When Emma gets into Jay's car for the first time, she has random braids in her hair. When she gets home and is talking to her parents, she has no braids. When she goes to the ravine, she has braids again.