Given that he had rented the facility from a hotel that had done that in the past, and the atypicality was mainly in the secrecy and set design they wanted, I d

Given that he had rented the facility from a hotel that had done that in the past, and the atypicality was mainly in the secrecy and set design they wanted, I don't think that it's unreasonable to expect that the hotel had all of its permits in order. It's a reasonable mistake -- though one that, as you point out, should have been caught by his wedding planner.