Mm, indeed. I have written letters to the dead (and then burned them ritually to send them on their way). So I was aware of the possibility.

I just didn't think that was the case with the letter to Draco - and so I misread this one. Because it wasn't addressed to Antosha himself, as many of his other prayers have been, but to Draco, in a public fashion, I thought he was deliberately sending a message, saying, "Yes, I know you're alive, and I'm going to protect your classmates, but in case anybody's reading my journal I will obfuscate this somewhat."

But! I'm wrong. That's OK too.