This - seems more than an innocent mistake. It's either gross negligence, or someone (possibly after a heavy night drinking) thinking that such a move would be "SOOOOOOOOO funny, man!"
I hope the person in charge of the music is relieved of their duties as soon as possible.
Seconded.
Thirded.
What a class act. I wouldn't have blamed her for a bit of drama, but she is just plain grace personified.