On the Bard building he left the metal untreated so it would rust to blend in with its surroundings. *shakes head*

I know switching where the shiny metal was at the last minute on Disney Hall left the city open for a lawsuit from that poor woman whose apartment registered well over 125F. The move meant the sun reflected in on her apartment and turned it into an oven. Gehry just thought it was more artistically pleasing to move it and didn't bother to run any checks.