I think this something that does happen in real life, especially in the past when we used to have a regular postman, who knew people by sight. Although now we do not seem to keep the same postman so long, I do not know. I have frequently taken the mail from the postman in the street outside my house even when it was a postman I had never seen before. I think they are just glad to get rid of stuff, and save themselves the trouble of puting it through the letter box, even though they probably meant to. Perhaps in the case of Stephen the postman had seen him at the factory, or had had to go in to hand over a parcel. For myself.f I saw nothing unusual in handing it over in the street.