If /bin/sh is a link this has to work as well:

 noether:/ # ll -G  /bin/sh 
 lrwxrwxrwx 1 root 25 Mar  4 09:43 /bin/sh -> /etc/alternatives/_bin_sh
 noether:/ # ll -G  /etc/alternatives/_bin_sh
 lrwxrwxrwx 1 root 11 Mar  4 09:43 /etc/alternatives/_bin_sh -> /usr/bin/sh
 noether:/ # ll -G  /usr/bin/sh
 lrwxrwxrwx 1 root 20 Mar  4 09:43 /usr/bin/sh -> /etc/alternatives/sh
 noether:/ # ll -G  /etc/alternatives/sh
 lrwxrwxrwx 1 root 13 Mar  4 09:43 /etc/alternatives/sh -> /usr/bin/bash

... note that the last link can be also any other bournce shell like

  /usr/bin/dash
  /usr/bin/ksh
  /usr/bin/mksh
  /usr/bin/obosh

or whatsoever we have around