What's more, in the back half of the season, Rhimes says Heigl asked her to write Izzie light so she could shoot her movie, The Ugly Truth.

FORBES: In Defense Of Katherine Heigl

Instead, Rhimes explains that in the first half of the season, Izzie had a very strong storyline with George that played out a lot more comedically than the character's story lines had in the past.

FORBES: In Defense Of Katherine Heigl

While Ugly Betty creator and executive producer Horta comically suggests that Rhimes put Heigl's character in a coma, the Grey's show-runner says she has an "unbelievable" story arc prepared for Izzie in the show's upcoming season.

FORBES: In Defense Of Katherine Heigl