I've learned from a similar mistake.
Last summer i was delivering to the RCMP barracks in my city and in one department the security guard signs for all the pkgs being delivered to that department. There is this one elderly lady who has had a run in with EVERY driver who has delivered to her, and I was no exception on this day. After ignoring her condecending tone and sarcastic remarks I asked her for her last name. She said nothing, crossed her arms and gave me a stare that could turn Jesus to stone, so I thanked her for her time and went on my way. On the way back to the truck I typed "grouchy old lady" into the clarify field, just for giggles of course. Well sure enough the guy who the package was for had not recieved it in a couple days and went online to track it. When he saw that "grouchy old lady" had signed for it, I immediatly recieved a customer complaint. Funny thing is that the union steward backed me, saying that since the lady refused to give me her name, I had to describe her somehow. Ever since, I have used caution when clarifying signatures, resorting to using Jones, Johnson, Smith, Brown, etc.