He would have done something like this.
1. Opened index.php
2. Found<div id="left">
<?php mosLoadModules( 'left', -2 ); ?>
</div>
3. Change to<?php if ($option != "com_expose") : ?>
<div id="left">
<?php mosLoadModules( 'left', -2 ); ?>
</div>
<?php endif; ?>