Q: Do you ever have people get mad at you because they think you are ignoring them? Then how do they take their foot out of their mouth after that?
A: Excellent questions! Yes, it has happened to me and the usual reaction on their part is "He is so rude". How did I know that? The look on their faces and their body language when I finally do acknowledge their presence. To answer the second question, my experience tells me that you should use the "Oh sorry I didn't realize" approach and treat me the same respect that you show to everyone else.