This is my second attempt to add a few words. The first time I took too long to compose my thoughts and the screen timed out and my thoughts were lost!!
My initial thoughts on watching DLG were what a disappointment. However, after getting this out of my system I went back and watched the episode a couple of more times. I am glad I did. Even though the story was pretty poor and the GD link wrapped uo way too tidily, I saw some great acting by George Eads. There is so much non-verbal communication in this episode. The body language is everything and the words very little.
I read in an interview that George Eads gave at the end of season 5, that he wanted to see Nick in Season 6 become callous to the point of uncaring. Where Nick could no longer see good in anything and that this might even get him into trouble.
To me DLG indicates that George’s thoughts are coming to fruition. I’ve been thinking for a time now that Nick ‘changed’ after Gum Drops. Up to Gum Drops he is coping with his ordeal in Grave Danger by going about work much the same as always. He has convinced himself he is ok and moving on. It catches him out every so often, like with going down the bunker, but he is generally in control. He is hiding it well from his colleagues. However, the circumstances of Gum Drops tweak Nick’s fragile emotional state and he loses control big time during the interrogation of the offender. The fact that Sarah observes this weakness makes it all so much worse. We know from past experiences Nick does not open up to others and is a private person. Sarah even highlights too him that he would not have behaved in that way 6 months earlier. I think Nick was scared, and also ashamed by his loss of control and has, intentionally or otherwise, since this point regressed deeper into himself. He has buried his emotions as deep as he was buried in Grave Danger. He has become more insular from his colleagues. Warwick even notices enough to call him ‘Grissom’ in PofTR. (which of course we have not got to yet!)
In DLG there are so many reasons Nick should be emotional – he has been kept in the dark about the tape, Archie knew but not him, Kelly has come back to haunt him, he learns his kidnapping was only about money, Grissom thinks its all over just because the suspects are deceased and then Kelly commits suicide in front of him. The ‘old’ Nick would have worn his emotions on his sleeve, everyone would have known if he was angry or sad. Now he is ‘cold’. No barging into Grissom’s office – he has to be summoned. Lemon-grass has already highlighted the tensions during the meeting. But Nick never loses his cool; he unnerves Grissom with his calm tones and ‘poker’ face. Nick has the upper hand when he leaves the office. There was never any chance of him showing the weakness shown in Gum Drops. Nick has made sure of that.
There are visible signs that Nick is troubled on a sub-conscious level. I agree with the comments above that the checking behind him is one of those signs. It has been happening a bit in Season 6. He was caught unawares and grabbed from behind when he was kidnapped, and now in moments of stress he subconsciously checks behind him.
That’s what I like about DLG, there is so much we learn about where Nick is now, but not so much from his words, but from his body language. He is not in a good place and it looks as if it is going to get worse for him!