You dont give us much information to make a fair judgement- could have just been a one of incident. But anyway, I dont think that it is child abuse!
You know - we are all human, even teachers & support staff - everyone has their "off" days. And come on - it's a fact of life that we have all at some point been blamed for something that we didn't do.
Also malicious or not I think your daughter should have been told off for stabbing someone with her pencil - regardless of why it happened, even if it was a quick "You need to be more careful & not use your pencil in that way" Otherwise they (classmates) will all learn that it's ok to hurt others "because it was an accident."
This is the most stressful term for teachers, getting to know 30 different personalities of different backgrounds, abilities etc. Yeah "your daughter/the pencil incident may have been the straw that broke the camels back."
On the other hand if the shouting is constant & excessive it may just be that the member of staff needs to work on her behaviour management strategies & if this is the case, the school would have already picked up on this & will be addressing it.
I also wish if parents have a problem they go straight to the teacher to discuss it, I dont think that there is much to gain in asking on here as you don't always get the answers that you are looking for (as you have found out)