So the lazy sod in question has ignored a century of advice that prelims are important and got 25%. Their assignment may or may not have been sparkling; we'll never know. They've done unit tests and A/B tests throughout the year. If at Higher, they presumably did well at N5. Their teacher, who looks upon the youth with a kindly eye, sees a spark therein and bumps up his grade, sensibly, along with the rest of the class. What's the problem here? If historically the schools predictions have been iffy then some or all of the bump will get adjusted, if they've been good, then his result will be waved through. And if he doesn't like the final result, he'll apply at post results to have his assignment marked properly.