I think any (financial crime) case built solely on computer evidence is too weak to be prosecuted, even if that means you end up accepting some non-zero amount of financial crime. "it is better a hundred guilty persons should escape than one innocent person should suffer" as someone once said.

In the case of the sub-postmasters the Post Office, as far as I'm aware, never proved where these stolen sums supposedly went. The computer evidence was thought terminating and was the only thing (except false confessions under duress) used to secure these convictions, rather than proper investigative work.