Just my thought since I only watched the last 15 mins or so and haven't seen the tape and from reading what you all had to say.
Regarding what Grissom would have done, vs what Catherine did, does anyone remember the episode "Strip Strangler" in this case the "Sheriff" removed Grissom from a case when he refused to go along with him and the FBI. At the press conference she warned him when he spoke.
LYNDA DARBY: Mr. Grissom-- As the lead CSI on this case, do you have anything to add to the FBI statement?
CATHERINE: Politics ...
(GRISSOM glances at CATHERINE.)
GRISSOM: (to LYNDA DARBY) No.
LYNDA DARBY: (to GRISSOM) So, Las Vegas can breathe easier? You do have the Strip Strangler behind bars?
(Unwilling to lie, GRISSOM answers her.)
GRISSOM: No, we don't.
By going with the truth what did it get Grissom?
GRISSOM: Oh, do I get the weekend off?
SHERIFF MOBLEY: For starters, and a two-week holiday, anywhere but CSI. You brought this on yourself. Now, the next time you want to play with my career, maybe you'll think twice.
Could it be that Catherine remembered that situation, Grissom didn't play ball and it got him kicked from the case, and Catherine in charge (I know that is what you all are thinking but I remember catherine telling grissom.
GRISSOM: You don't want to be a Supervisor?
CATHERINE: Well, if I get a promotion, I want it to be on merit ... not because you're politically tone-deaf.
In short while from what knowledge I have it seems to me comparing what Grissom would have done, to What Catherine did do or didn't do, it just seems to me that they are two different people, who have two different approaches to their jobs, who compliment each other in the essence of balance she reminds him of politics and he reminds her of the boundries. OF which BOTH have screwed up on at one point or another. Not to mention comparing would be like comparing oil to water.
She is the acting supervisior but her hands were tied, say she told them, it comes out, busted and removed then what? I have to say in one respect yes should could have said to heck with it and told them, but by not doing so she gave them deniablity if it all headed south. They could be the ones to come in with fresh eyes if that was the case. She knew the hurt, but she knew her team no matter what happened they respect the job.
As to Catherine being out of her whelm I liked that idea, she wasn't acting like the catherine we know the writers made her different, guess what thats sometimes a good thing, its called change and growth and learning/falling and learning again, everything people need. Nick wasn't exactly the good old nick, a mutiny? taking charge over and asking Warrick, Sara and Greg to join him, he is changing and evoling and again something everyone needs to do at some point.