Sounds like your dog was afraid of her and your wife may have inadvertantly reinforced that fear (there's another thread about alpha rolls that you may want to look at).
The good side: Your dog didn't bite and he didn't snap. He was scared but he displayed his fear in other ways.
The bad side: Obviously you don't want your dog doing this.
In future (if you're going to have him out in these situations): Have the fear-provoking person ignore him. Have the fear provoking person offer him a treat when he's not acting aggressively. Help him learn that people who look different are a wonderful thing and nothing to be worried about.
I'd hesitate to experiment with other peoples 12 year olds for liability reasons, but perhaps you could enlist a dog savvy friend to dress up and recreate the situation?
The good side: Your dog didn't bite and he didn't snap. He was scared but he displayed his fear in other ways.
The bad side: Obviously you don't want your dog doing this.
In future (if you're going to have him out in these situations): Have the fear-provoking person ignore him. Have the fear provoking person offer him a treat when he's not acting aggressively. Help him learn that people who look different are a wonderful thing and nothing to be worried about.
I'd hesitate to experiment with other peoples 12 year olds for liability reasons, but perhaps you could enlist a dog savvy friend to dress up and recreate the situation?