Where did he go?

My wife had an unnerving experience at her store last Thursday. She said the day had been rather quiet only a few buyers. At one point when there was no one about she decided to take care of some paperwork, It was early afternoon and the door to the store fronting the parking lot was closed. The only other door, in front, is permanently locked. The store door has a loud bell that rings when anyone enters. We made sure it was loud so we could hear anyone coming in if we happened to be in the rear storeroom. My wife was working at the cash register area which is directly beside the door. The bell had not sounded. Quite unexpectedly a voice got her attention. A tall, slim, nicely attired middle aged man dressed in a western style even to the cowboy hat remarked how nice the store looked and went on to say he had not been "back" for quite a while and how everything had changed. My wife said they talked at some length about the area and how it use to be. At some point his eye landed on a comforter that was displayed and my wife walks around the register area to further show the piece. After discussing the matter, he finally said he needed to move on and my wife waked him to the door which he then exited. My wife says she was only three paces behind him but when she got to the door the man had totally disappeared. Those who are familiar with our store knows we have a large parking lot and there are no objects like trees or building near it. At that time, only her car was in the lot and it is parked well away from the door for customer convenience. Yet this man walks out the door and disappears before my wife, taking only three steps can see how he leaves. So what gives here? How could he disappear so quickly? There is a clear shot from our parking lot in all directions for 100 ft. or more. Unless he sprouted wings and flew, how can this be?