This occurred at a 141 school. Student passes PPL, then while instrument training lands an RG gear up. Typical investigation , insurance claim occurs. Ok, no problem. Then student continues training in a different aircraft and passes Instrument checkride with a DPE. Then goes on to pass single engine Commercial with a DPE. Then goes on to pass Multi-Engine Commercial with a DPE. Then... 6 months later FAA says, Hey we need to conduct a 44709 Re Exam for your Private Pilot License... uhmm.. that was 3 licenses ago. FAA says turn in your commercial license, it is no longer valid until the 44709 Re-Exam for your Private Pilot license is completed. Can anyone please shed light and explain why, after 3 additional checkrides, that this is not absurd. thank you for your time.