Yes, it's wrong.
 
	 
	Right code:
 
{{if \IPS\Member\Group::load( $comment->author()->member_group_id )->g_icon }}
				<li class='ipsResponsive_hidePhone'><img src='{file="$comment->author()->group['g_icon']" extension="core_Theme"}' alt='' class='cAuthorGroupIcon'></li>
			{{endif}}