When Gordon yells at Michel right before storming out of the Secret Garden, his shirt is monogrammed. When we next see him, he's stepping out the side door wearing a plain shirt.
During one of the moments when the restaurant owner is talking alone into the camera and to the viewing audience, he is complaining about the changes that Chef Ramsay made to the menu. These comments are supposedly made AFTER the restaurant had already been remodeled since he's complaining about that night's dinner service in the re-modeled restaurant. Yet, we can see behind him some of the knick knacks and decor of the old restaurant.