Copier Room Body Language - Awkward!

We have all either been in a situation like this or witnessed something similar...

Today after lunch I was at the sink washing my fork and tupperware bowl when I witnessed a very awkward interaction between two coworkers of mine - we will call them Bill and Shirley.

As I was approaching the sink to wash my dishes Shirley was just leaving the microwave with her food. She approached the refrigerator just as Bill rounded the corner to get something off of the copier (located right next to each other). You could tell Bill was pressed for time and was not interested in talking. Shirley, however, looked eager to start a chipper conversation. I didn't catch any of the actual conversation, but the body language said it all. Bill, papers in hand,  was slooowly backing away with and periodically turning his head as if he was looking for the quickest way out of Shirley's path - sort of like a cornered baby monkey being stalked by a hyena. Shirley meanwhile kept creeping her way closer and closer to Bill until she finally trapped him in the corner of the copier room. She looked creepily accomplished.

is it possible that some people just cannot read body language? A normal person approaching Bill could easily tell that he did not want to be bothered - he was in the copy room to get his print outs and head back to his desk to work. Maybe if he backed up faster and turned his head faster she would have gotten the hint...after all she was wearing glasses and maybe she couldn't see his body language?