I am not a lawyer, but I doubt refunding your fraud victim after the fact gets you off the hook for fraud. If the victim or the police wanted to pursue that.
I think it might make it difficult to prove intent to defraud if you immediately return the cash. Is it theft if a magician picks your pocket but then returns the wallet at the end of the trick? By the most technical sense of the term, it might. But i can't imagine a prosecutor that would go after something like that.
I see what you're trying for but I don't think the magician analogy is accurate. Bare minimum you agreed to sit and watch the magic show, and every time I've seen a magician involve the audience they always start with "Can I get a volunteer?", at which point it's clear you're a willing participant (yes, you don't know what's about to happen, but the magician gives the wallet back after so it's clear about the entertaining show and not an example of the magician attempting to commit a crime)
> Is it theft if a magician picks your pocket but then returns the wallet at the end of the trick?
If a "street magician" randomly picks my pocket out of the blue, you can bet I consider that theft, even if they give it back afterwards. They'd better get my consent to do anything with my person or my property.