I’m not super comfortable approving his work, but its functional and I don’t want to hold up sprints…

I know it’s not the point of your post, but this is a red flag to me. If you’re using scrum (which it sounds like you are?), a sprint isn’t defined as “when all the stories get to done”, it’s a set block of time (generally between 2 and 4 weeks). If the stories don’t get to done in the time period, you don’t hold up the sprint - they just didn’t get to done. Most teams will just refactor the story into smaller pieces to carry over to following sprints.

Ah, but when the bad employees make messes that you then need to clean up? Or someone makes a mistake and everyone on the team gets reamed out because “we’re a team and someone should have caught that, so it’s everyone’s fault”?

I’m a software engineer.