Yes prevention is smarter and that's why AntiOnline is here.

So I ask, are the issues Jareds brought up enough to indicate that other subnets on the same network are at risk?

Is it enough to fix the vulnerabilities that one student found? Or should the fix be to PUSH for the district to provide more instruction, training and support to their staff who are being used as 'IT' probably without proper compensation but with all the responsibility and potential blame.