Add term to custom post type on draft

I’m trying to automatically add a custom taxonomy term to custom post type when the custom post type of property is created. The action is firing but it is not adding the term. I know it is firing because I’m using Debug Bar Action Hooks plugin.

I’m also getting the following errors:

Warning: Missing argument 2 for add_locked_term() in /nas/wp/www/staging/jmoreilly/wp-content/plugins/custom-properties/meta-box.php on line 448

Warning: Missing argument 3 for add_locked_term() in /nas/wp/www/staging/jmoreilly/wp-content/plugins/custom-properties/meta-box.php on line 448

Notice: Undefined variable: post in /nas/wp/www/staging/jmoreilly/wp-content/plugins/custom-properties/meta-box.php on line 449

Notice: Undefined variable: post in /nas/wp/www/staging/jmoreilly/wp-content/plugins/custom-properties/meta-box.php on line 450

This code is in a plugin and it appears that those variables are not yet created at the time the action is fired. What might I be doing wrong?

Here is my code so far:

function add_locked_term( $strOldStatus, $strNewStatus, $post ) {
 if( $post['post_type'] !== 'property' )
     return;

        $term = 'locked';
        $tax = 'Status';
        wp_set_post_terms( $post, $term, tax); 
}
add_action( 'transition_post_status', 'add_locked_term' );

Can someone point me in the right direction?