You have a contact form on the contact-us page, but there is no such doubling of code there. The two forms seem by the look of them, to have been made with different versions of the form builder. We haven't seen the project files for the forms (and I'm no expert on FormBuilder anyway), but since I can't find anything weird with the SD file, could it be the version of the FormBuilder that you used for the reservations form?
Unless Eric finds something that I have overlooked, I think I'd like to see those form project files.
Inger, Norway
My work in progress:
Components for Site Designer and the HTML Editor: https://mock-up.coffeecup.com