Yeah. I've owned and been around dogs my whole life. We currently own a Great Dane and a Staffordshire Bull Terrier. My wife competes in obedience trials regularly the the GD. And I can't believe it when people claim to "know dogs" and then proceed to attribute cognative thought and human traits (like being vindictive) to them. It's compeltely ridiculous. I can't believe I need to explain this to someone who <cough> "knows dogs" but when a dog develops fear for and aggression towards a specific person it's not being "vengeful" or "vindictive". It's a conditioned response and the animal is acting on instinct and reacting to its owner's behavior and other circumstances in its immediate surroundings. Maybe you oughta read a book or two on dogs if you're going to try to pass yourself off as someone who knows what they're talking about. Here's an article written by a canine behaviorist on the topic that might be a good place for someone who obviously knows nothing of the topic to start:

http://www.barkbytes.com/training/human.htm

If you'd like to learn more about this topic, let me know and I'll post some more links.