He denies 12 different things in that extract. Entrance, shooting, removal of silencer, exit.
So no surprise he denied cycling The Sea Wall.
Deny being the key element. That is the first point anything about the sea wall was put to him in almost 13 months. There is nothing reference the wall in the police interviews but there is talk of the bike.
Wilkinson undertook his route experiment in October 85, Bamber was already banged up on remand awaiting trial then. As said earlier all routes were undertook as all routes would have been deemed a viable option. Settling on the sea wall at trial on the account of nobody seeing him ( 500 people interviewed in the locality)
Maybe a jury visit at 2am would have been beneficial.