misinterpretations?

Yesterday I was in the elevator on the way to my unit when a lady with a phone came in. The recording on the phone was playing and she said in a fed up tone to it "oh shut up". Then she smiled at me and said hi. I think she thought I thought she was telling me to shut up. I knew she was frustrated with the recording because that's what you get now for 15 min when you try to call customer service