How to say “Politely admit forgetting” professionally

Level 1: My apologies, that specific detail isn't immediately coming to mind. Could you please refresh my memory on the context or provide any relevant documentation? I want to ensure I have all the necessary information to proceed effectively.

Level 2: I'm reviewing my notes from that period, and the specifics of that request aren't readily apparent. Perhaps we can quickly align on the original scope or any subsequent adjustments to ensure we're both operating from the same understanding?

Level 3: While I've cross-referenced my action items against the last meeting minutes and the updated RACI matrix, I'm not locating a formal record of that particular directive. Could you point me to the specific documentation or communication where this was formalized for my records?

Level 4: I do not recall that specific request, and it was not captured in my current sprint plan or agreed-upon deliverables. To avoid any future misalignment, let's ensure all critical tasks are formally documented and prioritized moving forward.

Level 5: Never heard of it.

Level 1: My apologies, I don't have an immediate recollection of that specific point from our previous discussions. Could you please provide the context or refer me to the meeting notes where this was outlined?

Level 2: While I'm reviewing the comprehensive project documentation, that particular detail isn't readily surfacing. A brief reminder would be greatly appreciated to ensure we're perfectly aligned on all aspects of the current scope.

Level 3: Upon careful review of the signed Statement of Work and all subsequent change orders, I'm unable to locate any formal amendment or record pertaining to that specific requirement. Perhaps it was an aspirational discussion that wasn't formally integrated?

Level 4: That item was not included in our agreed-upon deliverables or any formally approved change requests. Any new requirements would necessitate a scope adjustment and potential re-evaluation of the project timeline and resources.

Level 5: Wasn't in the contract.

Level 1: My apologies, I don't seem to recall the specifics of that conversation. Could you kindly remind me of the details, or where we documented that particular point?

Level 2: I'm drawing a blank on that specific aspect. It might have been discussed alongside several other priorities, so a quick recap would be very helpful to ensure I'm fully up to speed.

Level 3: Fascinating. I've been diligently tracking all collaborative commitments in our shared project management tool, and that particular item doesn't appear in my current view. Perhaps you could re-share the link to the relevant discussion thread?

Level 4: I don't have any record or recollection of agreeing to that. Moving forward, please ensure any requests requiring my action are clearly communicated and confirmed, preferably in writing, to prevent misunderstandings.

Level 5: You must be mistaken.