OK, lets run with the idea that brokering a deal can mean a lot of different things... fine.
If you are going to broker a deal like this, where the discussion is about establishing a new govt while the present govt is still in power, think about how long that would take? Think about the amount of trust you would have to have in the guys on the other side of the table. If you are the Crimea opposition, you would have had to built up enough of a relationship over a significant amount of time that you can trust Russia as you essentially make seditious plans in the Ukraine... essentially putting your life in their hands. Likewise, if you are Russia, you would have to build an equal amount trust with the Crimean opposition in order for your plans to not reach Kiev and create an international firestorm.
So this wasn't something that could have been scratched out on bar napkins over a few glasses of beer. There had to be a significant amount of planning involved with this.
Would you at least agree with this assumption?