One interesting point, for me at least, that he brought up was the way adventure game characters often maintain the same pose no matter what is going on around them, and/or flash in and out of "action" poses when needed, but then go back to the same rigid pose as before.
I actually kind of prefer this to the twitchy random body language that a lot of triple-A games try to do fluidly: like rolling backwards and forwards on the feet slightly while stationary and inactive.
It's a game. They are game characters. I don't really want them to be constantly swaying around. I find that more distracting and offputting than just staying still until I need them to do something.
An occasional brief idle view is nice, like brushing hair out of their face, but the constant body language that a lot of games try to do often just reminds me more that they are not real people.
It's like in a book if the author attempted to describe to me every second sentence exactly what the character was doing with every limb on their body.
There's probably a balance somewhere in the middle as well, but for now I prefer stationary (with occasional idle view) characters way more than hyperactive constantly swaying ones.