The destiel hand print wasn’t possible?

Ok, so we’re all really familiar with the hand print Cas left on Dean’s shoulder in season 4

you know the one

problem is, Cas didn’t get a vessel until after he pulled Dean out of hell, after he blew up the gas station and sam’s motel room

He even explains that he thought Dean would be able to see him without his vessel: “That was my mistake. Certain people, special people, can perceive my true visage. I thought you would be one of them. I was wrong.”

So why the hand print? If angels are really the “wavelengths of celestial intent” that Cas says they are, and that they’re just the big balls of grace we’ve seen, can we really assume that it’s Castiel’s mark on Dean’s shoulder?

For all we know, it belongs to a demon trying to drag him back down, instead of an angel pulling him up.