A gatekeeper designation ruling and a pending interoperability dispute are frequently treated as the same question. They are not. One determines who the Digital Markets Act applies to; the other determines what standard of evidence a regulator will accept once it does. This article examines the distinction the European Commission has already drawn, and the structural parallel it carries for pre-execution evidentiary architecture.

Reconstructing what an AI system did is a forensic capability. Proving what was authorised before it acted is an architectural one. The governance documentation market — law firms, consulting practices, compliance frameworks — sells the first. Enforcement proceedings under AI Act Article 99 will demand the second. This article establishes the structural distinction between evidence-based governance and proof-based governance, and why only one survives adversarial scrutiny.