Bug in Celtic Queen?

I have the Massacre Blade and am trying to kill Hok Braz in Celtic Queen. The first time I hit him with the sword his HP went to zero, now nothing I do will kill him. Is this a bug or is there something I am missing?Help!
The forum for all Redshift games.
http://www.linux.redshift.hu/forums/
http://www.linux.redshift.hu/forums/viewtopic.php?f=3&t=2513