If the responsible party engaged the practitioner itself and a requested representation is withheld, or the representations cannot be relied on, or the competence, integrity, ethics or diligence of the people giving them is seriously in doubt, the practitioner discusses the matter, reconsiders the integrity of those involved and the effect on the evidence as a whole and, if the matter is not resolved, qualifies the opinion, disclaims it or withdraws.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.