If you get in the middle of a dog fight (doesn't matter what breed), you get bit. They are focused on the fight, not the human.
All but one dog fight I've had has been over food. Keep them separated when food is around. Also, when I have two that have had a fight, I separate them for a few days when I leave. The one fight I had that was not over food (I am assuming Rob Roy trounced on Austin), I separated them the rest of their lives when I was not there.
I hope your DH heals and understands Loki was not aiming for him, but the other dog.
I remember tripping once and as I was trying to stop from falling on Shadow for some reason I screamed, scared the crap out of him (I must have been quite a site flying through the air at him and screaming) and he bit me. I had several bites on my head. Fortunately, I didn't land on him. He was the sweetest guy and I never had a problem with him afterwards.