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.

Clearly there was no intent to defraud. He was testing for a security issue and promptly returned the money of the one person who was fooled.