The last odd thing I encountered with a GDrag was I was fighting a guildie in town and there was some kind of trigger which caused my dragon to get guardwhacked despite guild filter. That was just after they came out. Wasn't bonded at that point so I lost a decent dragon. We couldnt figure out what happened...there were potions being used etc....we just couldnt figure it out
It's probably because the pet was fighting for longer than 2 minutes, without refreshing the flag (tamer saying 'all kill or guard'), It's like when you pvm something that lives long enough, your pet's bar/name will turn blue, and saying 'All kill/guard' will make the pets name green again if you're in a guild.
This happens in pvp, and results in tamers becoming the aggressor, which in turn can A) get the tamer guard-whacked. or B) the tamer is able to be reported for murder if the other player is killed.
If you flag someone as a tamer, and they turn blue before you have your pet attack them, you're pet makes you the aggressor.
It can be hard keeping a tamer blue if you pvp with one, unless you flag with your pet first and refresh your flag often.