Had never heard the story.. and I'm no chicken sympathizer as I've ended more than a few in my lifetime... but seems like a pretty cruel deal to not finish him off at the time.  I'm sure the farmer just didn't understand the brain stem was where it was and just thought it was some miracle the thing continued to live, but dang.  A chicken is about the dumbest animal on earth, one without the ability to see, hear and feed itself had to be a miserable existence.