display_override Hook, benchmark tags not working

[eluser]Unknown[/eluser]
I have this as a display_override hook.

Code:

$this->CI->output->set_output(
            $this->CI->load->view('head',array(),true) .
            $this->CI->output->get_output() .
            $this->CI->load->view('foot',array(),true)
            );
        echo $this->CI->output->get_output();

However, in foot, I am using:

Code:

<?php echo $this->benchmark->elapsed_time(); ?>

This is getting replaced with the {elapsed_time}, but nothing on actual output.

Any ideas?

[eluser]Unknown[/eluser]
*bump*