Journalist Nick Kochan described the raid as “massively audacious”.
He said the thieves drove away with £53m, but left £154m behind, making it potentially a £200m robbery.
With £32m still missing, Kochan says much of that cash may have been absorbed into general circulation, now “floating around in our shops, in our pockets, in our banks”.
Some money, he said, went on the “high living” of those later jailed, while other sums went into organised crime, including drugs and counterfeiting.
Anti-laundering systems today would flag large deposits or attempts to move large amounts abroad, he said, but two decades ago, the system “wasn’t there”.
“Unless you strike very quickly and find that money… your chances of it being brought back into the legitimate system have to be decreasingly positive,” he said.