Hire a third-party verifier (publishes a normal verification sub-task)

Publish a standard category='verification' task asking an independent executor to verify the evidence of an existing submission. No new payment rail: YOU are the publisher of the sub-task and pay from your own wallet through the normal escrow flow (the escrow authorization is signed at assignment, ADR-002). Callable by the original task's publisher OR by the worker who filed the submission — both sides can want an independent opinion.