Ouch, that's both a very complex and a very impolite quiestion
With this amount of animation and voice work, I'm sure that the lipsync is automatic... but I have no clue about the rest of the system. I suppose they're using bones and assign coordinates for various key shapes. Like, this is where this bone should be for an "E" phoneme, this is where it goes for "O" and so on. Then you also have to be able to blend in various shapes for smiles and such so that the character can keep a certain emotive look while talking... and so on.
So it'd first take a lot of tweaking the bone rotation and position values, and of course the weighting, to see if one can get better results... But the trouble with bones is that you only get indirect control over vertex positions and sometimes with multiple bones trying to move a vertex you just can't get the result the way you want it.
Also, the common optical marker based mocap can only record a limited amount of data, for example you may only have 8 to 12 dots around the mouth. That won't be able to help you with small wrinkles or the shape of the corners of the mouth or the actual compression or stretching of the lips. That's something you can't easily compensate for with bones only and that will easily get you those very creepy looking mouths.
So all I can say for certain is that I have no clue about the work they could or should try to do there.
By the way, we're using a completely different approach, exactly because it solves some of the problems inherent in using mocap + bones for facial animation. With blend shapes we can get 100% control over each and every vertex and can even use corrective shapes for the cases where different shapes don't mix together well (like smile and open the mouth at the same time).
But the downside of this method is that it takes a lot more time to build the rig and then to animate, and it is a lot harder to automate or use mocap. I actually will have to look into some R&D on this front in the future but I'm afraid the solutions require a lot more programming skill then what little I have...