I can't find any reference to a lifetap, must have been some other NPC I was remembering.
These logs do show something else being casted by him though:
http://www.antonius-bayle.org/index.php?topic=3452.0
http://www.moemoe.gr.jp/~yourtoy/onlinerpg/eq0105.html
First log has some spell being cast at [Fri Feb 15 00:20:38 2002]
Second log has another spell cast other than Grav Flux between [Thu May 03 02:32:19 2001] and [Thu May 03 02:33:23 2001]
Recast is way too long for Grav Flux (1:04) everything else shows 32-36 seconds.