wp_editor adding stylesheet

In 3.5 RC-2 it seems it is inserting a stylesheet when inserting wp_editor() on front-end of theme:

<link rel=’stylesheet’ id=’buttons-css’ href=’http://mysite.com/themename/wp-includes/css/buttons.min.css?ver=3.5-RC2&#8242; type=’text/css’ media=’all’ />

The styles overrides the .button classes in the theme style.php.