I had a fellow senior developer that worked for 2 months on implementing an important feature and he had clear instructions of how everything had to work (loadi

I had a fellow senior developer that worked for 2 months on implementing an important feature and he had clear instructions of how everything had to work (loading sequence, retry mechanism, error handling etc.). We launch the feature and shit hits the fan really quickly. Turned out he left out a few requirements and had another developer approve the review without looking too closely to meet the deadline. I was super angry and I didn't feel like swallowing my anger because this was really disrespectful.