I recently had a conversation with a couple of other instructors at UT about what to do when you've realized you've made a mistake about a student's grade, especially what to do if you've assigned a grade that is lower than what the student actually deserves.

Oftentimes, as younger or less experienced instructors, we have a tendency to believe that we cannot change a student's grade for the better because then they'll always question our grading practices, and then we'll have to deal with lessened authority in the classroom and constant requests for grade changes.