Mr Walker wrote that TfL had not followed its own rulebook, in particular by failing to tell “all the relevant people” that the power supply was about to be switched on.
He added: “This would have given the (Metropolitan) police and British Transport Police an opportunity to confirm that Mr English had not been found and was likely still on the railway side of the tracks.
“It is likely that had this step been followed the power supply would not have been switched on and a proper search, which was also possible, is likely to have found Mr English and returned him safely to the station.”
The police watchdog ruled in June 2024 that an investigation was not required.
In April, TfL was urged to deliver a “concrete plan” to prevent intoxicated passengers being killed on its network following the accidental death of an artist in a Tube tunnel after a night out in London.