Code reviews fix this problem. If someone removed an important check from my code, I'd mention it in the review and ask them to revert the change. And if not me, someone should look at the changes and wonder "Was there a reason for this check?". Of course people aren't perfect and mistakes happen, but with reviews, tests, and documentation, you can make mistakes like this very rare.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.