You are correct. An error of this sort should never happen at such a high profile event. I just saw on the LA Times website that there are always two cards - one for both sides of the stage. I have not read the story yet, but they have several articles on how it happened. I went there since I assumed LA Times knows how to cover their local industry. However it happened, Steve Harvey is probably a bit relieved at the moment.
Steve Harvey should be ecstatic. He is no longer the biggest screw-up in awards history!
Interesting. That would explain why the two cards. Thanks for posting.