[BUG] Claude caused preventable data loss by contradicting its own plan

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude wrote a migration plan that explicitly stated old DynamoDB tables would not be deleted until after migration was
verified. However, the Terraform changes it wrote renamed existing table resources (changing variable defaults), which caused
terraform apply to destroy the old tables and create empty new ones — before the migration script ran. Claude then instructed
the user to run terraform apply first without warning that it would destroy tables with data.

Root cause: Instead of creating new Terraform resources alongside the old ones (allowing parallel existence during migration),
Claude modified the existing resource names, making destruction implicit in terraform apply. This directly contradicted its own
stated plan.

What Should Happen?

Claude should follow it's own plan. Safeguards should be in place for non-idempotent actions especially permanent deletes.

Error Messages/Logs

Steps to Reproduce

There are too many paths to consider. but likely it is:

• create a plan for AWS to migrate data
• discuss awhile with claude the next steps; get claude to lose it's train of thought
• return to the migration and terraform apply

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.50 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_