These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Moral Event Horizon: Max Tyler's a Jerkass from his first appearance and an adulterer to boot, but what really takes the biscuit is his physical abuse of Phillip.
School Governor Ralph Mellor hits it when he tries to swap his daughter's positive drug test for her boyfriend Marley's clean one (saving her place at the school and his reputation, and getting rid of Marley in one go), and then goes far beyond it when he attacks Marley with a golf club and later drives a mechanical digger into the school.
Lewis crosses it when he tries to burn Jack alive.
As does Barry when he starts people smuggling.
Small-time bullies Lisa and Shaznay well and truly cross this line when, in the culmination of an appalling vendetta against Gabriella - see Trauma Conga Line on the Main Page for the full rundown - , they crash her house party and utterly destroy the bedroom of her deceased sister with sadistic glee. It snaps Sue out of being an unprofessional Jerkass towards Gabriella and even disgusts Kacey who has more reason than anybody to hate Gabriella.