That's true for OW but the OP is talking about RescueThat's not a requirement anymore. PADI instructors are not required to keep a copy of the OW Knowledge Reviews. The instructor must attest to having seen the completed KR and sign off. That's it. I do think they are required to keep a copy of the KR's for continuing education.
Knowledge Reviews
Each section in the PADI Rescue Diver Manual ends with a knowledge review.
Student divers must complete knowledge reviews prior to the corresponding
Rescue Training Session. You must review any questions
missed or left incomplete until the student diver demonstrates mastery.
After a thorough review, have the diver verify understanding by signing
and dating the statement on each knowledge review. The PADI Rescue
Diver Course Prescriptive Lesson Guides is a useful tool for reviewing the knowledge
review questions. You must document completion and review of Knowledge
Reviews in the divers permanent records (Student Record File recommended).
Since these are no 'check boxes' on the SRF for Rescue Diver this leads me to believe they must be turned in.