We know how the Four Horsemen robbed the bank in Now You See Me, and we know the French guy was preselected for the trick.
But how did they convince everyone (the French guy included) that he was actually in a safe in Paris?
This is actually explained by Thaddeus Bradley when he examines the trick with the FBI afterwards. The French guy (who was preselected because of the exact bank they needed) was not teleported. Instead, the "teleportation device" he was placed in just threw him right under the stage, where the Horsemen built an exact replica of the bank safe's interior.
Thaddeus: I personally prefer to take the stairs to Paris. Welcome to the City of Light, Agent Rhodes.
Rhodes: So they got a vault set...And it's the exact replica of the little French guy's bank...
Thaddeus: He was a dupe, not a plant. They chose him. They knew which seat he was in...He was selected. They programmed his mind to make him go to Las Vegas. And then they kept reinforcing it, until he did. They trailed him. They studied him. Nothing was left to chance. He had no idea he was their target. And they simply activated him in Vegas.
So he just walked around under the stage the whole time, thinking he was in the actual bank safe. And as you already explained yourself, the real bank was robbed much earlier (or actually not really robbed, but the money just exchanged beforehand).