Just had fairly similar situation just yesterday.
Was walking down the street when a taxi pulls up right next to me and honks his horn, i turn to look and he's looking right at me, so i stop for a secon before walking to the car door. As i go to open it he shoos me away as i realise he's just beeping his horn to let the resident behind me know he's outside. Honestly thought he wanted directions or something...felt so embarrassed as he drove past, I just knew he was regaling the story to his passenger about the idiot who tried to get in the taxi.