You aren't looking closely enough at the messages he got:
Code:
[HP: 100%] [ME: 24%] [PE: 100%] [Wealth: zero]
s
You walk south.
Hallway
A long hallway continues here, spanning the entire length of this upper
wing. The hardwood floor and paneled walls are rather comely, though a
lesser degree of care appears to have been taken on this floor than was
obviously had below. Doorways are present on either side.
Obvious exits: n e s w
A wary male half-elf walks in from the north.
[HP: 100%] [ME: 24%] [PE: 99%] [Wealth: zero]
Yes, a charmie will flee out if you walk out of the room during combat. However, in this instance it didn't even give time for that to happen. This wary half-elf is scripted to follow the bad guys. That's what he's doing here. Just like when any old shmoe is following you, when you walk into the next room, what you see along with the room description that you've just walked into is the "A wary male half-elf walks in from the north." message. If he had been tracked in it would have looked like this:
Code:
[HP: 100%] [ME: 24%] [PE: 100%] [Wealth: zero]
s
You walk south.
Hallway
A long hallway continues here, spanning the entire length of this upper
wing. The hardwood floor and paneled walls are rather comely, though a
lesser degree of care appears to have been taken on this floor than was
obviously had below. Doorways are present on either side.
Obvious exits: n e s w
[HP: 100%] [ME: 24%] [PE: 99%] [Wealth: zero]
A wary male half-elf walks in from the north.
[HP: 100%] [ME: 24%] [PE: 99%] [Wealth: zero]
This was not a NPC tracking someone who fled. This was a NPC following someone into the next room via the standard "follow" command, even though he was engaged in combat.
Bug.