grumpy pedestrians

I was walking three abreast on a room-for-four-abreast sidewalk, and was deep in a conversation with a coworker.  I saw a woman coming directly at me, made eye contact, and she seemed to glare boldly ahead, but it's the city and I don't expect people to be friendly.  There was room to my left, but I turned sideways as she passed so she would have more room, seeing as she didn't alter route at all.  As she passed, she said, "What?  You can't share?"  I understand her position, and I certainly could have been more polite, but there was room for her and I felt like she went out of her way to be rude.  When I walk alone I try to walk around groups and not through them.  I suppose all I can do now is not pass on the grumpiness.