Our 5yr male Bernese (he's not neutered) just lunged at a 7yr girl. Her family was a guest at my place. Her and her 5yr old sister were wearing large puffy scarfs. He didn't have an issue with the younger one, but when for the neck/scarf of the older one. I pulled him off of her. That was an attack for sure, snarling, teeth, etc.
This dog is otherwise very friendly. My 3yr literally sits on him and he's there like a rug. Our 7yr old cat sometimes annoys him and nothing happens. He's otherwise a very docile guy.
What the f* happened? Was it that the kid has a little fear of dogs or was it the scarf? He's no longer trusted with visitors and will be locked in the garage during their visit.