This happened to me day before yesterday. A friend asked me to accompany her to a doctor's appointment and told me she would show up at my house at 11 a.m. I told friend that I would have Baren walked and be ready to go at 11. I came back around 10:50, secured Baren, and saw that friend had called at 10:30, saying she would be there in 15-20 minutes. At 11:05, I called friend, asked her if she was on her way. She replied yes. I said, "Oh I was afraid I had missed you." She snarled, "You did. Goodbye" and hung up on me. Now, friend knew I was walking the dog and what time we agreed upon. So, she must have arrived early, waited 2-3 minutes, then tore out of there like banshees were on her heels.
I haven't heard a word since, so I know she's still angry. DH says she must have wanted a reason to be mad at me, so she wouldn't have to reciprocate with a b-day present. I was there at the agreed-upon time, so I'm not going to grovel because she was early and wouldn't/couldn't wait.