How to code Doom 4 Finishing moves with interactive animations

Here is a link to the game play footage i mentioned in case someone hasn't seen it. Every time there is a (ill just call them "mini cut scene") between two interacting objects, for example the demons, or when he prys open a door and you actually see his hands come up and open it. Even when he picks up the shotgun, the object doesn't just appear in his hands or in the inventory he actually picks it up, loads it, and you walk off. when there is a button and he attempts to press it, his hand comes out and touches it, triggers the sound que and doesn't open because of the wrong finger prints.

Thanks again!