Thats a very good point. Who says the ‘act’ happened inside the flat. The bag could have been used to transport his body discreetly/neatly with the external surface cleaned down carefully before lifting into the bath. Two blokes could have carried the bag and it’d been chosen for sealed/cleaniness/strength.
I use a similar Mountain Equipment one and its been amazing for over 5yrs (No spies carried).
The bag was used/known to be good, there was no hair (if you murdered someone you’d leave at least a hair in the flat unless you KNOW to avoid this- ie a pro). If it was kinkiness gone wrong the other person would be flustered/leave something behind.
Me thinks he came in the back of a van, carried in in the dead of night, the heating whacked up to aid decomposition/to cover any tracks/traces etc)..
I think it was a sign. A pro would have made him look like an accident, the dresses/wigs weren’t enough- almost an amateur ploy so maybe his love of dressing up WAS real but the murder was meant to be obvious to the MI6?