Story: Risk Rolls Downhill - The Software Bug That Sent People to Prison

October 2, 2025

54 min episode · 2 min read

Scott Darlington

Episode

54 min

Read time

2 min

Topics

Software Development

AI-Generated Summary

Published Dec 19, 2025

Key Takeaways

✓Software Bug Documentation: Fujitsu maintained internal known error logs for Horizon defects like "Calendar Square" but never shared them with postmasters or support staff, leaving victims defenseless.
✓Risk Distribution Pattern: Large organizations systematically push liability downhill to contractors and small business owners who lack resources to fight back when systems fail catastrophically.
✓Government Procurement Failure: Massive IT projects fail when optimized for compliance over functionality - Horizon rolled out to 14,000 locations simultaneously without proper testing phases.
✓Whistleblowing Responsibility: Software engineers must speak up when they know systems harm people - corporate compartmentalization doesn't absolve individuals of ethical responsibility to act.

What It Covers

Scott Darlington's story reveals how Horizon software bugs sent UK postmasters to prison while Fujitsu knew about defects but blamed victims instead.

Key Questions Answered

•Software Bug Documentation: Fujitsu maintained internal known error logs for Horizon defects like "Calendar Square" but never shared them with postmasters or support staff, leaving victims defenseless.
•Risk Distribution Pattern: Large organizations systematically push liability downhill to contractors and small business owners who lack resources to fight back when systems fail catastrophically.
•Government Procurement Failure: Massive IT projects fail when optimized for compliance over functionality - Horizon rolled out to 14,000 locations simultaneously without proper testing phases.
•Whistleblowing Responsibility: Software engineers must speak up when they know systems harm people - corporate compartmentalization doesn't absolve individuals of ethical responsibility to act.

Notable Moment

Fujitsu engineers nicknamed a recurring bug "Calendar Square" and logged it internally while postmasters faced prosecution for the same system errors nobody warned them about.

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