As a former dog owner, I've experinced a lot of interactions like this with other dog owners, where everyone's main attention is on the dogs - maybe eye contact or a little smile/wave for the person. So I wouldn't describe the basic behavior as rude, especially since I think it's at least widely expected, even if it's not necessarily dominant. However, none of that really matters because as you said in #3, it's a very simple problem with an incredibly simple apology to make if you actually WERE feeling friendly and excited to meet someone and failed to communicate that impression to them. Not only is race irrelevant, it's awfully telling that her main desire wasn't to apologize and correct the mistake.