Guess that's what I get for not actually watching the video and just reading the comments.
"I find it very sweet that Kiri does this major mess up at 5:50... especially in an aria she could sing in her sleep.
Nevertheless she and maestro Levine find one another a couple of agonising bars later and the smile of relief at 6:07 (Thank God we are back together again) is obvious in her face..."
Then I just watched 5:50 seconds in now but I have no idea what it supposed to be like so I can't tell if she messed up or not. She kinda pauses for a sec so maybe that was it?