Comment Possibly not stolen (Score 2, Insightful) 108
From the linked screenshots, the alleged borrowed assets appear to be shaders or bumpmaps and such. That is, tools for the map developer that the gamer doesn't "see" per se.
Perhaps, like sound effects, companies license the use of such "tools"? I know I've heard the same gunshot noise in 500 movies and video games, and that crazy death scream...