Recently I was incapacitated by a mob when I was taken to -1% hp. Two things were strange.

1. While I couldn't say, tell, etc. in my incapacitated state, I could continue to use gtell to communicate with my group.

2. When I finally died, I took no xp loss even though it was a mob that incapacitated me.

1. We're nice that way. Gtell is a different form of communication than tell, and we let you use it while incapacitated. It's one of the perks of being in a group.

2. Normally, if you're incapacitated by a mob, that mob will still be hitting on you and will kill you. It sounds like your group mates managed to kill the mob but couldn't heal you in time. So, even though a mob incapacitated you, your wounds killed you instead of a mob. It doesn't quite make sense, but we're willing to let it stand that way. Another "we're nice that way" scenario, if you like.