yes, deaf are more aware of their surrounding- we have to be, but we also tend to be too focused on a lot of things too (like lipreading or watching out for something).
Other than that, She probably felt you weren't minding your business? I don't know for sure though. I wouldn't worry about it though as she probably thought about her action and regret it. If the guy wanted her to move, he should have come up with his own solution instead of yelling at her and depending on other people to get her attention (I mean what if no one was there but him? He'll have to get her attention somehow). I think she probably was embarrassed that he created too much attention that you noticed it too.
This happened to me the other day. This woman asked me to move, and I was looking at the labels on the food for allergies, and when I didn't hear her, She yelled at me that startled me and everyone around me. That was quite embarrassing. The woman in front of me thought the woman was yelling at her too (she was blocking just as much as I was). The woman said, "No you are ok, I was talking to her" in a loud voice. I did not like her attitude at all
If you need someone's attention, be subtle about it.
I just thought of someone, usually when someone wanted my attention, the person near me would give me a light tap on the arm (only if I'm reading or something) and point me to that person. They usually left the rest to me to figure how what the person wanted. It seem that I don't have a problem with this method.