Incorrect data after modifying post using backlink from wp_die

I don’t know why this issue occurs. The back_link is created in /wp-includes/functions.php. If there were a Javascript solution, it could be applied in the message of wp_die. For example:

$msg = 'Error' . "\n<p><a href="https://wordpress.stackexchange.com/questions/80375/javascript:history.go(-1)">$back_text</a></p>";
wp_die($msg, 'Error',  array( 'response' => 500 ));

But this didn’t work…

What I saw is that the Title and the default Custom Fields meta box are the only ones that don’t preserve the value when the browser goes back in history.
The Content, Custom Meta Boxes with Custom Fields, the Category and others preserve the value.

A workaround is putting your Custom Fields values inside a Custom Meta Box.

Observation: when hooking in the save_post action, there are some checks that you need/may do:

add_action( 'save_post', 'myHook', 0, 2 );
function myHook( $post_ID, $post )
{
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE
            or ! isset ( $_POST['post_type'] )
            or 'post' !== $_POST['post_type']
            or wp_is_post_revision( $post_ID )
        )
        return; // <-- NOT the correct action, stop hook

    $post_meta = get_post_meta($post_ID, 'data', true);
    if ($post_meta)
    {
        // _validation_function();
    }
    else 
        wp_die('Error, please enter Data Field.', 'Error',  array( 'response' => 500, 'back_link' => true ));
}