Euthanasia not execution

As we all know California recently executed their oldest death row inmate. Clarence Ray Allen asked for clemency because he believed it cruel and unusual to execute a frail old man. He suffered from diabetes, was nearly blind and deaf, and had suffered a near fatal heart attack in September. So heres my theory...he wasn't executed, he was simply euthanized. If he was that hard off then we simply ended his pain. And we all know that euthanasia isn't considered cruel and unusual if he was really suffering. So therefore it was not an execution! If he was really that frail then we shouldn't have been paying to keep him in jail. Allen was convicted of murder and then hiring a hit man to murder one witness and two bystanders. Simply put it was either put him to death or keep spending federal money on keeping such a frail and suffering man alive. Euthansia isn't an execution, it isn't cruel or unusual, in fact its basically humane.
*Giving credit where credit is due, my mother actually came up with this theory. I just thought I'd share it with you all and embellish on it.*