I think you're right. There's some other evidence that it was the wrong Arturo too-- in the mobster episode, he wanted to keep the bribe money and take it with them to the next world, while all the other characters wanted to return it. Also in the Kromagg episode, he had to sell his watch to the French restaurant to pay for their meal, but the right Arturo had dismantled his watch to repair the timer on the anti-technology world back in the second season. Even the reaction of the one who got left behind-- it was a shocked and concerned, "Oh my God!" The wrong Arturo would not have reacted that way about being left behind on his own world-- he might've been angry, but not shocked.But the wrong Arturo isn't really a "bad" Arturo, he's just a different one. Over time, he learned to love the other sliders just as the original Arturo had, which I think was a great character development arc.