OPS.15:5.2 - A favorable bound can settle the reporting decision
Consider a separate forty-request cohort with the same 90% objective. Thirty-one are known timely, seven are known late, and two have unresolved completion timestamps. The most favorable result is 33 / 40 = 82.5%, if both unknown requests were timely.
The cohort missed the objective under either interpretation of those two timestamps. Further lookup cannot change that classification. The practitioner reports the supported result and the remaining range, from 31 / 40 = 77.5% to 82.5%.
The missing timestamps may still matter to contacting those recipients, recovering service or correcting a source defect. Continue that work for its stated use without making it a prerequisite for the already settled cohort judgment.