I think that standardized testing is a necessity. The reason that teachers get up in arms over bad scores and statistical errors is because the scores of the school reflect on them as teachers. There is really no other way to make sure that the state funded schools are up to par.
On the other hand, your friend should not have to deal with angry teachers because she made a mistake. There is no reason for them to take it out on her.
I always performed well on standardized testing, and my high ACT scores gave me numerous advantages in college from a research position as an undergraduate freshman to my tuition covered by scholarships. In that regard I will have to respectively disagree that standardized tests aren't important. With that said, I understand that some people just don't do well on them.