I interpreted the scene in Scarecrow the same way you did. They both didn't think the other would do it, so they both went through with it, waiting for the other to stop first (which consequently never happened). And so when they were trying and failing to call one another they really wanted to make up, but the stubborn side was still lingering.

I'm just happy Sam realised there's more to it than that and went back to help Dean. *snuggles them*