Thanks for your great comment. All those ways that monsters are acting out of character -- it is good to step back and look at the list. At the same time, as a contrarian it makes me wonder if monsters ever really did act in character, or if Hunters were just making generalities and assumptions?

I think your point that a reaper would come for Sam, and that Death was his reaper, seems like a good one. We have seen that when Bobby was near death, and when Dean was near death, that reapers came to convince them to move along. If Sam was putting up more of a denial, I would say that the reaper was absolutely sent for him. On the other hand, Death said some things that were a little out of character as someone else pointed out, primarily that it was up to Sam to choose -- usually reapers do not offer a choice, but rather urge the person to move on and not hang about to become a ghost. I think the scene works well either way and I think it's fascinating that there's no real way to get proof, until the next time we meet Death walking about.