There were a number of endings cut together at different points.
The theatrical version I saw had Sam stuck in a tortured fugue state with hallucinatory clouds and blue sky behind his head. That was a concession backing off from an even darker version without the sky, just the torture chamber.
AFAIK the happy-ending version was only shown on TV once or twice. It’s basically a fan edit except the fan happened to be a studio exec.
True enough, and he could string a coherent sentence together without having to read out what someone else had written. So there’s really no comparison between him and Little Fingers, except maybe in terms of morals.