Access raw Eloquent mutated attribute value in Laravel 5
The method you look for is getOriginal. To get the original value you might use:
$this->getOriginal('some_bar');
In model is defined this var:
/**
* The model attribute's original state.
*
* @var array
*/
protected $original = array();
It's protected so you should add a function to get original's values
(not tested)