For my opinion, I don't expect DC to be any more forthcoming than he has been. I will not hold my breath for him to show any character other than the character he has already shown. I do expect DC to do what will benefit DC.
You're so right. I was actually stunned (not to mention revolted) by the number of flagrant lies he tried to sell to LE during his interview. But what really stood out to me was that he not only lied about his searches on Suburban (to protect himself and the A's), he was also willing to lie about activities at the Ritz--particularly his own hour-long conversation with the network rep in the lobby. In this instance, I assume he had to be lying to protect Cindy, since he's entitled to chat with anyone he chooses.
Because of that and some some other behaviors involving Cindy and him, I can't help wondering if his feelings for Cindy go beyond professional loyalty. If so, he may be willing to lie and jeopardize himself at any cost rather than "throwing her under the bus." That means he won't dare to incriminate Lee or Casey or George, either.
He certainly doesn't strike me as a "noble" kind of guy, and he's indisputably dishonest, but I'm not holding out any hope that he'll cough up any damning, truthful testimony against any of the A's.
I sure hope I'm wrong about that, though.