I remember when almost all teleision was "live". Boobs popped out of too tight bodice, pants dropped (which is why you should wear suspenders), babies wet themselves and others, animals defecated, stage hands slipped on it, psychotics had breaks, and the bi-polar never got a chance to do a full show!
Janet now says it was an "accident" ~ that part of the costume was supposed to break away revealing "red lace".
If that had been pre-recorded they could have done it over and over until that happened. As a live television stunt, it was high risk ~ and these two people are too young to remember why it was an elementally stupid thing to do on a stage in front of millions.