Saw this in the local news this morning...
http://www.wftv.com/news/news/local/student-found-weapons-orange-co-elementary-school/nZ8DK/
No idea what this 9 year old was up to, but definitely weapons, and some ill intent.
The lack of detail, and refusal to clarify the incident by your principal, implies it was much more serious, than it actually was. Shining a light, is a disciplinary event? Does she mention it was a flashlight, or imply a laser? Records should be accurate, factual. Wonder how many other parents are having the same or similar problems.
She made the knife incident out to be a whole lot worse, than it really was, and she was being a far greater threat to your son's future. A weapon in school, could very much effect his chances of getting into other schools, financial aid, employment. He's 9 years old, no telling what direction his future would go, and this isn't helping. We tend to believe the schools have our children's best interest in mind, and that they will make those records sound as nice as possible, considering the situation. You principal, is just the opposite, and limiting your son's options at an early age. 9 years old, that principal, is still going to be ruining his life for a few more years...