What you described with your dog sounds exactly like my chihuahua, Mia. She ONLY gets that way when she's with one of her people - me, hubby, or my little girl. One time she even jumped off my lap and latched onto my boxer's face and wouldn't let go when he was walking past me.
If you can imagine that...a 5 lb chi getting downright vicious with an 80 lb boxer. She's very lucky that he's such an easy-going dog and that he just took it all in stride instead of swallowing her.
The major problem I'm having now is Mia with my older female cocker, Bailey. If I'm holding Mia and try to give Bailey any attention, Mia will attack her, and Bailey will attack back. I hate them fighting, especially because Bailey is getting old (12 this year). I know this is a jealousy thing with Mia because the dogs are together all day long, sleeping, eating, and playing and they never show any aggression toward each other. It's only when a person is involved.
Anyway, didn't mean to rant about my own problems, but it sounds like your dog and Mia need to go to anger management together.
Hopefully yours was a one time thing!