Apparently Spike's crypt has an outer door and an inner door. I watched the dailies on YouTube last night and was somewhat disappointed to see that the door Spike was caressing was NOT the door Buffy was touching. But it's a minor thing mostly, and doesn't lessen the impact of the scene AT ALL.

I meant it literally. Spike's cript has an outside door (the one that Buffy is touching) then a very small foyer, and then another door (the one that Spike is touching). I don't seem to remember which episode it was that I realised it, but you can see it quite nicely.
On the other hand, as far as this scene goes, I'd say it is a continuity error, since we're clearly meant to perceive them as touching the same door. Don't mind me, I'm just doing a bit of nitpicking. :)
B.

Heh. eowyn_315 wrote up some illustrated meta on how Spike has two doors. :)