Sasuke's incident was neither too big nor too small.
The person he attacked was a leading instructor. Although only at the Chunin level, that was already quite impressive in Otogakure, a village with a relatively small ninja population.
A student attacking a teacher was wrong in principle, but since it happened in full view of everyone that the other party had started it, pinning down right and wrong revealed that the other side was at fault first.
Chapter 209