there's one part i can pretty much gaurantee you that it's not ingame or in-engine, which is where Hale kicked the hatch open. kist look at the perfect ray traced lighting and ultra smooth shadows, the uber high res textures on the metal, it resembles some of the Lair's CGI. but the rest of the teaser could be entirely in engine with touched up AA. there're definetly some flickering artifacts on the bridge model and some shadows poping on the mothership on top left. i really hope they'll deliver that kind of rendering quality in the real game though if not more.
It didnt look THAT great to me to be implied it wasnt in engine although it looked awesome.