undefined | Better HN

0 pointsfoldr8mo ago0 comments

UK law said that there was a presumption that computer systems were working correctly unless there was evidence to the contrary. That’s not inherently nuts. It makes roughly as much sense as assuming that, say, a dishwasher is in working order unless there’s evidence to the contrary. This presumption in and of itself could just as well aid a person’s defense as hinder it (e.g. if they have an alibi based on computer records).

In this case it should have been very easy to provide evidence to override the presumption that the Horizon system was working correctly. That this didn’t happen seems to have resulted from a combination of bad lawyering and shameless mendacity on the part of Fujitsu and the Post Office.

Don’t get me wrong — the whole thing is a giant scandal. I’m just not sure if this particular presumption of UK law is the appropriate scapegoat.

0 comments

mrkramer8mo ago

>UK law said that there was a presumption that computer systems were working correctly unless there was evidence to the contrary.

Defense had to prove that only one Horizon/Fujitsu accounting software was buggy and the whole prosecution falls apart e.g. If John's Horizon/Fujitsu accounting software has bugs then Peter's Horizon/Fujitsu accounting software most probably has bugs too.

mike_hearn8mo ago

IIRC one issue was that every time someone advanced the theory something was wrong with Horizon, the Post Office kept claiming that nobody else was experiencing any issues. They also lied under oath, claiming no bugs that could cause such situations were known. Given this most the of defence lawyers abandoned that line of inquiry (they were nothing special, seeing as village postmasters aren't rich).

buzer8mo ago

Proving bugs can be pretty hard if you don't have access to software & source code. That is similar to the US, courts usually won't give you access to source code to verify if software is operating correctly, you generally only get cross examine the company representative & person who performed the test. DNA tests are one good example.

One case where defense did get access to the code (FST developed by NYC) led to discoveries (https://www.propublica.org/article/federal-judge-unseals-new...) that led to it being retired from use.

foldrOP8mo ago

In principle, yes. It may be that the bar was set too high and that there needs to be some clarification of exactly what the presumption means.

I’d argue that some kind of weak presumption along these lines clearly makes sense and is probably universal across legal systems. For example, suppose the police find that X has an incriminating email from Y after searching X’s laptop. Are they required to prove that GMail doesn’t have a bug causing it to corrupt email contents or send emails to the wrong recipients? Presumably not.

j / k navigate · click thread line to collapse