We just listened to a speech by a military man who was said to represent the officer corps in the Ukrainian military. He said that if the blood of any one of these innocent protestors is shed, the military would turn itself on the ones who shed it. In other words, the government. That was as direct a threat to Kuchma and Yanukovych as you are likely to get.
UPDATE: The Periscope identifies his man as Deputy colonel Grigory Omelchenko, the head of Ukrainian Officer's Union. (Is he any relation to the Kiev mayor?) It doesn't appear that he is in the cahin of command in any way, but it is evidence that the military is not monolithic in its support, if indeed there is all that much support for Yanukovych and Kuchma there in the first place.
Chain of command may not make a difference anyway. In revolutions, when control and authority breaks down, chain of command can break down too. So it may may not be the issue it might otherwise be.