Contribution in WvW is too dependent on the capping ring
Tagging the boss and not getting a medal at all is serious butt. +1 to OP
User was infracted for being awesome.
Honestly you should still be able to get bronze or silver without even fighting the boss. An equally important roll is to clear the walls/defenders out so that a force can go and take the tower lord. If you are doing that you may end up with no reward at all which is messed up IMO.