"You just don't seem like someone who'd use violence." Competent teacher my foot, that's how abusers get away with their violence. Meanwhilst their victims get doubted due to how odd they seem (they're victim to abuse, go figure).
Like, I get that MC is innocent here, but the portrayal of the adults here isn't unrealistic due to their competency; They're not competent. They've decided one faction is right before confirming what actually happened (granted, you rarely get the full picture) and are fully throwing their support behind him, throwing caution and neutrality to the wind.