I was in Lt Get AT in the second room when all of a sudden i started to get a message that said "Your target has moved" and the skeleton I had been fighting had disappeared. My avatar continued to try and strike at the missing creature and I kept getting the same text on screen. Then the skeleton reappeared and I could connect. Several (I think 7) skeletons respawned at that same time. This happened on Drizzt at approx 8:30 pm CST on 04/07 in case you need any of that info to look into logs.

All NPC's get refreshed from time to time. Good for when they wander off too much, get in an odd state, or whatever.
Looks like your skeleton refreshed midfight....
He should be fine for a few days now, and then...

These are tough to find.
There is not enough data in the logs to track this sort of issue and unless I can repeat it I can not add the debugging code required.