1. Thought we had a problem in production (serious but not urgent).
2. Decided to be fixing in the production branch (although envisioned it would take long which could have been seen as a clear warning).
3. Changed it substantially (redeploying to a copy of production).
4. Then the REAL, urgent problem came. And we had out production branch un-deployable to the production.

Should have branched production and worked in the branch from the start.