Actors need to have exceptional control over the emotions they portray on-screen. The raw and real feelings experienced by the characters in Grey's Anatomy make the series that much more believable.

But even after years of controlling emotions shown on screen, no actor is immune from losing their cool from time to time, after all, they're only human. After years and years of filming for Grey's Anatomy, it's no surprise that a fair amount of drama has taken place behind the scenes.

There have been lots of petty disagreements as well as issues surrounding creative differences, but nothing too crazy. Imagine fans' shock when finding out about the drama between the most popular long-time male character on the show and the creator of the show herself.

Grey's Anatomy creator Shonda Rhimes is a highly respected name in her industry and ultimately a force to be reckoned with, but this, unfortunately, didn't deter actor Patrick Dempsey, who played the iconic Derek Shepherd, from clashing with her.

Shonda was not the only person Dempsey had caused friction with, but she would ultimately be the last.

Other castmates have revealed in interviews that there had been incidents of on-set tension caused by him for a long time leading up to his departure. There were claims that he outright terrorized the set of the show, and his complaints of how time-consuming filming was, got under Ellen Pompeo's skin which caused clashes between the two stars, who ironically played husband and wife.

Isaiah Washington also revealed during an interview that the infamous fight between himself and Dempsey was over the latter constantly holding up production by being late.

So, after causing numerous issues and creating an uncomfortable working environment, Shonda Rhimes saw first-hand what others had been warning her about for a long time. It was the Grey's Anatomy creator herself that gave executives an ultimatum: "If he doesn't go, I go."

With the season 11 finale, it was obvious that Derek Shepherd would no longer be a part of Grey's Anatomy as devastated fans watched Meredith pull him off life support following a horrifying car accident.

Sadly, Grey's Anatomy had to lose the dreamy Derek Shepherd over the drama caused by Patrick Dempsey's attitude on set, but ultimately it was a choice that worked out for the better. Dempsey was able to spend more time with his family and work on other projects and the castmates he left behind were able to work in a more peaceful environment.