Comment by buzer

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.