Really? I doubt records were destroyed, the CC list on any government project is a long list of email addresses, the simplest and more likely scenario is the records were never created. If no forms, then logically no inspections and sign off were carried out, so what has MTR been doing for the last few years sitting in the office waiting for forms?
Normally, a monthly progress and management report is prepared, circulated to all parties, so everyone knew the records where missing.