What is Accountability vs Responsibility?
Accountability is answering for the outcome — it belongs to exactly one person and cannot be shared or delegated away. Responsibility is doing the work — it can be spread across many. RACI encodes the distinction: many R's per row, one A, always.
Delegation's iron rule follows: you can hand someone the task and the authority, but the accountability stays with you. "I delegated it" has never once survived a steering committee as an explanation.
Worked example
The PM assigns the permit application to a coordinator (responsible). The submission misses a zoning attachment and the window closes for a month. At the review, the owner doesn't ask for the coordinator — the PM is accountable, answers for it, and fixes the checklist. The coordinator learns; the PM answers. Both things are true at once, and that's the design.