How do I prevent D7's ajax_deliver() from loading CSS? For some crazy reason, using ajax_deliver() in a menu callback is causing 4 theme CSS files to be loaded into my page, breaking the page styles. 

What I'm doing:


Using Seven as my admin theme
Created a basic admin page for a module
Admin page has a link (no form) which should return content via AJAX
Link points to a menu path which uses a custom callback
Custom callback uses the /nojs trick and returns content via ajax_deliver()


What's happening:


AJAX content is loading into the page just fine, working as expected
4 Bartik CSS files are being dynamically added to my admin page (using Seven theme)


Anyone experienced this? Any ideas on how I can prevent this CSS from loading?
Figured out the reason Bartik CSS was loading when the admin page was using Seven.

My admin page was located at /admin/mymodule/settings

My menu callback for the AJAX link was /mymodule/special-form

Because /mymodule is outside the admin area, the theme would be Bartik when actually visiting that page. So Drupal's AJAX system assumes I want the CSS that goes along with that page. Not a bug, but a feature to be aware of.