I've just seen a different version...Another cut of the film!!?

I've just finished the film, didn't understand the ending, then discovered this version I have (portuguese dvd, 84 mn), ends right after he discovers the killer of his brother is his current doctor. Then, overwhelmed by this discovery, he lies at the edge of the cliff, then the film backtracks with flashbacks until the beginning of the film, when he is talking to himself in the hospital bed (which we afterwards discover was a drem whitin the coma).

I went to youtube and saw the alternate (or should I say, the regular) ending, when the doctor shoots him in the leg, Arthur forgives him, then the doctor kills itself.

My question is: why should they bother changing the end, making it more cryptic, almost as if he's going to wake up again, starting everything again, dreams whitin the coma, trying to unravel again the clues from his subconscious?

Why not leave the (decent) ending you've all seen (more straightforward, more detectivish), and instead try to make it even more strange, surrelistic and, in short, not as effective?

It seems the only purpose here is to confuse the viewer, leaving him dumbstruck and scratching his head...

"The Sky above the port was the color of television, tuned to a dead channel."