I think before they will get a possibility of coming closer, some major s h i t may come down between them, intense stuff. The way Liz been acting mainly towards end of S2 I think she can expect some tough love from Ressler, especialy after him learning about her lies regarding Tom for example. I mean I don't think he can be emotionless, indifferent and all business with her at this point but I see him calling Liz on her bulls h i t. And frankly she deserves him saying to her face how dissapointed he is in her.
As you said I don't think she even realized how badly she was treating him and it's really the saddest part.
