Why blocklists can’t protect your Claude Code hooks

A user filed #40408 this week describing what happened when their model hit a deadlock. They had built 22 regex patterns across 3 layers blocking sed, awk, python inline, echo redirects, cat heredocs, tee, touch, rm, cp, mv, and more. The model respected all of them. Then it needed to fix a bug in its own safety system, and it used perl -i -pe.