In fb notes, how can a friend not see that i had a note where only he could read it?

I did not tag it, however I did have his name with that blue box that you are to use, and so i think he was notified either on his wall or on his globe notification thingy. I went to bed straight after and didn't check his wall to see if it was notified. It was something he said he did not get though. Does this happen?