At least most the game video was actually the game, sans some animations. Too often I've seen video for a game its just a cgi mock up and nothing whats actually in the game.
At least when it's CGI, you can tell it won't be in the game and those are mostly teasers anyway.
Now with the first Skyrim gameplay trailer, you couldn't possibly know which aspects would make it in the game and IIRC they stated that it was ALL actual gameplay....
When it was released Bethesda was up front that it was all made in-engine but some things were made for the trailer. I'm pretty sure they specifically mentioned special animations.
I don't think so...