One thing that is missing is the honeypot. Should check for differences between includes/templates/theme692/templates/tpl_contact_us_default.php and the file of the same name in the template_default directory.

As to the recaptcha, not sure if there is now some sort of cookie associated with recaptcha or if it is site specific, but I know there is a site that I frequently visit that uses a recaptcha and I haven't been asked to select or enter the verification information in quite a while after clicking the check box...

In fact, when filling out the contact us form at this site, once I clicked the checkbox, it didn't ask for any further confirmation...