Changes on test site erroneously applied on production site

I've just tried to create a new item (article) in the test site and this does *not* show in the production site, but if I create new types or duplicate templates, these changes will only be seen in the production site.

I really do not know if the name of the production site database might have been hard-coded in the joomla template (I imagine you mean the front-end template), as a guy was hired to set up the website. So I guess I will have to get in touch with him tomorrow and ask him if he made this kind of changes to the template used in the production site.

Thank you for your help, I'll get back at you tomorrow!