Yes, that’s right. My favorite idol screwed up on stage, and you know what? It makes me like her more. And that means you should, too.
I really don’t need to say when she does it… it’s completely obvious. Remember, this is the girl voted by the AKB48 members as the dumbest in the group.
’16 nin Shimai no Uta’ from Team K 4th Stage ‘Saishuu Bell ga Naru’ with Kobayashi Kana, Sato Natsuki, and Matsubara Natsumi. Filmed on November 28, 2008, Ono Erena’s birthday.
This video was provided by an uploader of the Stage on Veoh. I then posted it on YouTube without any mention of AKB48 in order to dodge any copyright problems. Sorry for the terrible quality.
Where's Natsuki? 
So was it at the very end? Or was it when she pulled the sign in the wrong direction earlier in the song???
Both. The funnier one is when Natsuki pulls the Ume/Mocchi board the wrong way, though.
I’m not exactly sure what is going on at the end of the song, but from what I’ve found, it sounds like Natsuki tries to talk about an animal, but doesn’t know its name, and the other two are questioning its existence. But that’s just going off of a really bad translating program.