The failures preservation exists to prevent are forms of spoliation: acting late once the duty has arisen, which can happen before any claim is filed or notice received; leaving routine deletion, auto-delete functions or the short-cycle rotation of backup media running after the trigger, which demands quick suspension; altering metadata such as creation and last-modified dates by opening, copying or migrating ESI, which is hard or impossible to reverse; making ESI unavailable through lost decryption keys, lost media or third parties who control it; and letting preservation lapse before the matter ends.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.