http://eventespresso.com/topic/my-template-file-is-stripped-from-the-body-class-on-single-events/

custom_espresso_template_slug.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file
// first get the template slug
function get_espresso_event_template_slug( $post_id = null ) {
	$post = get_post( $post_id );
	if ( ! $post || 'espresso_events' != $post->post_type ) {
		return false;
	}
	$template = get_post_meta( $post->ID, '_wp_page_template', true );
	if ( ! $template || 'default' == $template ) {
		return '';
	}
	return $template;
}

function add_my_stylesheet() {
    // now you can check for a template slug match
    if ( get_espresso_event_template_slug() == 'template-CFW-rt-sidebar-no-title.php' ){
        wp_enqueue_style( 'stylesheet_name' );  
    }
}

add_action( 'wp_enqueue_scripts', 'add_my_stylesheet' );