Why? The algo should obviously be public so if you went to court you'd question the algo or its impl, not the computer. After all, you only want restitution and correction of the issue, not punishment.
Given that, at least in the US, people had to regularly sue corporations that defend the secrecy of their fancy algorithms^W^W Excel sheets as trade secrets... that's not as obvious as you might think.
Why would that be? Health care providers, bail risk assessment software for courts, ... it's not like some public entity like the IRS would be likely to develop much in-house.
Try asking a computer in court what it was thinking when it ran the algorithm.