I find this most confusing. I wrote the book 'The Last White Empresses', which was published by Carmania Press in 2004. As part of my research for the book I spent a lot of hours in Guildhall Library in the City of London. I have copies of the Voyage Record Cards for the last 3 Canadian Pacific ships and also for the Empress of England as Ocean Monarch. I can see that Ocean Monarch departed Sydney on the 11th August 1970 and she made calls at Melbourne on the 13th, Adelaide on the 15th and Fremantle on the 18th. She crossed the Indian Ocean to Durban and arrived there on the28th and sailed the following day. She was in Cape Town on 31st August and sailed from there on 1st September. She was in Las Palmas on the 11th and then the card indicates that something happened on the 14th but there is no note as to what that 'casualty' might have been, it cannot have been anything untoward as she arrived in Southampton the next day. Unfortunately, on the 18th she sailed for the Cammel-Laird shipyard. The story of Shaw Savill may have been rather different had she not done so.
Anyway, I can see no record of that particular voyage from Sydney to Southampton being anything other than a regular, and uneventful, line voyage.