I think with some dogs you have to be extra clear who the alpha dog is...
My mom had a poodle...a miniature poodle but a pretty good size one...on the big side of miniature. She was sitting between my mom and my son who was three at the time. My son leaned over and put his cheek on the poodle's back. Didn't lay on the poodle, just gently laid his check over on her back.
That poodle growled at my son and showed her teeth.
My mom pushed my son away and pulled the poodle up to her face and said (in baby-talk) "Don't you growl! Don't you act like that!" then just covered it in kisses.
You know that both me and that poodle learned real quick where the poodle was in the pecking order. I never really trusted it again.
(I shoulda figured it out years before when I was on my way to my wedding shower and the dog jumped up on my brand new nylons...I told the dog to get down and my mom shrieked at me that if I couldn't get along with her dog I could just get out of her house.)
Interesting story. And it shows how ill-informed owners encourage continued aggression by rewarding the dog with affection after behaving unacceptably.