Whatever the reason, he was afforded the opportunity to learn and apply. It hasn’t come easy, but that’s the point. Giving a chance to redo isn’t about being easy.
Still in my standards-based grading vein, this is inevitably the biggest sticking point for teachers I work with.
"What do you mean they can retake the test for full credit?"
Mentally, we can agree with the argument that redoing work or retaking tests makes sense in the scheme of student learning. The hold up, I find, is more with the work involved in making those opportunities reliable and valid more than the mental exercise of finding value in the habit.
There are ways to allow students to reassess work that does not include sitting an exam again, which opens more possibilities for authentic learning and demonstration of mastery.