A police officer recovered the diary of Capt Collins, complete with all pages. That officer was not required to appear at the commission. When the diary was presented in court, all the pages were missing despite the good condition of the binder. The witness who presented the binder advised that he could not recall removing the pages!
No wonder Justice Mahon had doubts regarding some of the statements from some of the witnesses.
Many factors contributed to this disaster. There was no need to attempt a cover-up. The purpose of any accident investigation is NOT to apportion blame but to identify the cause so that steps may be taken to avoid any recurrence. Any cover-up negates the purpose of any investigation.