Game Mechanics: LD fighting - they time out too fast

[mimixownzall]

I was boxing and was fighting my two warriors level 2. I /quit on one of them and he kept fighting (like they are supposed to) and we duked it out. Well, after a few seconds (I would say 10 or less) he just poofed before combat was broken by either mine or his death.

Is this intended? I thought as long as combat was going you stayed in game until either you or the mob (person) you are fighting dies. That is how I remembered it.