I understand what you are talking about. Durring either releasing to spirit form OR rezzing to corpse, there is some error between the game server and clients where a character appears either dead or Out Of Range (usually stationary at some part of the map) but really that character is right behind you!

If it is an Alt losing track of your main, this spells doom for that Alt in the BG, as it can no longer follow your main or assist your main, because the Alts client thinks your main is dead/elsewhere!

If it is your main losing track of an Alt or and Alt losing track of an Alt, it is merely an annoyance, as the Alt is still following and assisting normally (although you cannot see your Alt's HP on the main's screen usually).

Unfortunately, the only way to remedy this is to immediately log (/camp) with the affected char and then rejoin. This will let you back into the battleground with the affected character, cured of any communication errors.

I will repost an explanation of how to diagnose the affected character when I regain equillibrium and am not longer intoxicated.