How Is That Not A Mistake?

I'm back at work after vacation, and my boss just left for his. One of the calls he handled while I was away is a ship out up north. Today I got a call from the receiving funeral home; the date of death is in question. Our paperwork said one thing, the family said they were notified a day earlier. So I pull the file, and see that, yes, the family seems to be correct, yet our face sheet shows the later date. So I call my boss, and he says the face sheet is correct. Then he hesitates, and says, "well, I got the call the day before yesterday. When would that be?" I told him that would be the date the family is indicating. He then tells me the stupidest thing I think I have ever heard in my entire life, and I can't wait until he rags on me for something dumb I did so I can throw it back in his face; "Well, I didn't make a mistake, I just wrote it down wrong."