No, the problem is greater than that. Decisions that affect people should not be made solely by computers or algorithms, and those decisions should be made transparent and auditable. If that leads to different/better ways of writing software, good. It's a larger societal issue though.
I think there's a lot of room for writing software better, including expanded source access for public systems and formal verification when critical.
But the failure in this case isn't technical, it's legal. It's rational to decide that occasional bugs in a mail software system are acceptable, and not worth the cost of designing a system's development around formal-verification. What's obviously insane is treating such a system as if it's bug-free beyond a reasonable doubt, and ruining innocent people's lives over it.
There are a lot of forms of gross incompetence and negligence that we're all fine with because they're so common. Failing to reason about software systems and their pitfalls, or consult with those who are capable of doing so, is an extremely-common and often-dangerous example (cf dumbass Senators grilling Zuckerberg with their 1970s understanding of how technology functions).
The blame here lies squarely on the prosecutors, judges, etc who are responsible for these verdicts. They should be ashamed of themselves.
Imagine not doing inspections of new building construction because it would be costly.