Having worked as a producer for many years, I have experienced many of the issues the BB production team likely dealt with last night. Here is my take on why Chima was more likely REMOVED as CBS suggests, instead of having simply quit.

There are a few things that need to be evaluated here;

1. When you sign up for a show like Big Brother, you have the option to leave at any time, what is not publicly acknowledged, is that there are limitations, for instance, you cannot DOR simply because you do not agree with the dynamics of the game. A DOR while it must be allowed, would constitute a breach of contract, and I assure you when the HG's threaten this, the first thing they are told is that they are of course allowed to leave anytime they wish, but a DOR under these conditions will be considered a breach of contract.

2. CBS is not the sort of network to simply 'let it slide'. While most of us hated Chima (I'm NOT a fan of hers, I've sent letters of complaint about her over the last week), she was an AMAZING television personality for the show, and drew in record numbers due to the drama, fights and controversy she caused. In effect, she was a cash cow for CBS, more viewers means more money and bigger budgets. By leaving, she will hurt the show in one way or another. CBS will not simply let this go and would very likely engage in some very expensive and protracted litigation. All of this would be explained to her when she made the DOR request.

3. Chima's behavior over the last 72 hours, had become increasingly unpredictable and volatile. Mic packs cost (depending upon the make/model) between $4000 and $10,000. I don't know the 'official' cost of the one Chima drowned in the Hot Tub, but purposefully damaging CBS property, is not something that would be taken lightly. I don't blame you for thinking, CBS doesn't care, they didn't talk to them all until hours later. You must remember however, disciplinary action is not taken immediately unless there is a health or safety risk to the contestants of the show. Likely, based on all the activities having gone on, this caused a production meeting where it was decided to meet with the House Guests. The reason for the delay was of course, you never walk into a volatile situation without a clear plan of action, so this meeting was likely thought out and planned, so as to be perceived as non-hostile by the House Guests.

4. It was likely at this meeting that Chima was advised she would have to pay for the replacement Mic Pack since she purposely damaged it. Given her apparent mental state, she probably "flipped her shit" and blew up.

5. Allison most likely decided at that time, that it was in the best interest of the network, the contestants, and Chima that she leave the show. When you're dealing with a guest who's behavior and defiance grows increasingly intolerable, you eventually reach a point where you have to cut them loose. It was likely at this point that Allison and Chima had a candid discussion (possibly heated), and Chima was cut loose from the show.

6. The house guests have all been saying that she quit. In truth, CBS quite likely hasn't told them yet what exactly happened with Chima, except to say that she will not be returning. Anytime information is given to the house guests, the production team must ask, will this help or hurt the show. In a case like this, it will do neither. So more than likely, it will be left at that, and the contestants may or may not be filled in in the wrap.

This is of course entirely speculative, and based upon my own experience in the media industry. I don't think they will hold Chima accountable for the Mic Pack, I think ultimately CBS will realize that they are dealing with someone who unfortunately responded poorly to the pressure of the game and the isolation, and decide to just let it go.