The more I think about this quote, the more insulting I find it.
"Yeah, the kid is going to shoot his mother in the head before she becomes a flesh-eating zombie......but, after showing the zombie c-section last episode and the human c-section this episode, not to mention the brains-on-the-walls gunshots & head-splitting ax blows & arrows through the eye socket, oh and also T-Bone getting chewed apart about 10 minutes ago, we thought that this might be too much. We wanted to keep it tasteful, you know.
Oh, and not too hokey, either. I mean, sure, we've had the 'Shane killed fatty?!?!' moment, the 'Sophia's a zombie?!?!' moment, and the 'Merle isn't dead?!?!?" moment, but we other than that.......no, it would be completely out of character for us to try to mislead or surprise our viewers."
I'm more inclined to believe either they were over budget or the actress had a clause in her contract that said she wouldn't be shown getting murdered by her TV son.