Discrimination against own race. Is it?..I think Not

Working in retail you come across many attitudes with people. You come across ignorance and all of the above every other day. Today work was different. At work having great customer service is checking on the customers and greeting them when they enter into the store. A lady from Africa comes in the store and I greeted her. She stops and says, " Sir Im looking for a shoe." I show her what she is looking for and continue to go back to work. To make a long story short, I went back to do doing whatever I was doing. An hour later, Im walking to the back of the store and see the lady browsing. I asked her was she finding everything ok and immediately she says " Sir just because I have this shawl on does not mean i have anything under here" I get very confused at the time. She then says to me, "Now you have been following me this whole time around this store (granted I wasnt and that she asked me for help as soon as she walked into the door) I didnt see you talking to these white folks in here. She continues to say, I have money, my money is just as good as theirs. I have a right to buy shoes where ever I want." I had to just pause for a second because never in my life have I been accused of discriminating against someone who is black like me. I had to calm myself down before I got an attitude with the lady. I basically let her know that it was my job to check on customers and see if they needed help with anything and not once did I follow her or accuse her of stealing anything. After that incident I had to think about maybe where she comes from things are different when she goes shopping somewhere. It just made me very upset that I was accused of discriminating against someone of my own race. I can say that day has changed my perception of a couple of things.