Dog attack in Lancaster CA

Dogs always get the blame if they show any aggression and bite someone. They're smart and can sense danger that isn't apparent to their owner. She mostly knows what I'm thinking when it pertains to her. I've had Pits and Rotties for about 18 years. We have a 94# Pit bull/mastiff with a kitten personality but is protective of our property. I hired a roofer to fix a leak and she was more aggressive toward him than I've ever seen..I should of turned her loose. He was a scammer..Charged over $1000. and didn't fix the leaks. Call it my imagination, fantasizing, whatever, but she likes every stranger that comes to the house. I'm not suggesting she knew he wasn't going to do the job but I believe she sensed his mental personality. That's my story and I'm sticking with it..:) :). .