Every response is scoped to one organization
Enforced by the database today
The response table carries an owner_org_id column, and every row belongs to exactly one organization. A district that registers as a single organization has every question set and response walled off from every other organization on the engine by that column, before any application-level check runs.
Evidenceqt_submission.owner_org_id (NOT NULL); the shared question-technology library scopes reads and writes by it.