So what happened?
We had a couple of house guests visiting this weekend. Loki had seen both of them before. The very first time he met our female house guest, he did growl. But this time, he was familiar with her and greeted her with tail wags and airplane ears. He was happy to be petted and scratched by her throughout their visit.
One evening, we were all watching a movie with all the lights turned off. With only the glow from the screen, our female guest saw that Loki was approaching her as if to just sniff. So she extended her hand, and as she did, he bit her.
The damage itself wasn't too bad, but it made us very apologetic and very upset.
I don't really know why he bit her. It was dark, and so, I guess that taught us to always be careful with Loki when you can't clearly see his facial expressions. Yun thinks that maybe it was redirected aggression due to Juju, as Loki is still prone to growling at her from time to time. Between the two dogs, the growling no longer escalates to full contact fights. It hasn't since July of 2009. We're pretty confident at this point that fights between the dogs are over with.
And I wish that I could say that bites from Loki are over with. But we can't. We still have to remain ever vigilant and cautious.