The Crimewatch Oct 1986 programme featuring the reconstruction was introduced by the presenter by saying that a lot of the facts had become obsurred by rumour and gossip.
The reconstruction being shown is based on entirely what is known.
The keys to 37 Shorrolds with its distinctive yellow key tag that Suzy had taken with her when she left the office was still missing.
I agree WiseOwl MG did not have the key when he visited 37SR that afternoon he knocked the door and looked through the window.
MOO