Attractive female students no longer earned higher grades when classes moved online during COVID-19
New psychology findings suggest that attractive students earn higher grades in school, but for female students, this beauty premium disappears when classes are taught remotely. The findings were published in the journal Economic Letters. ...
I guess any system could potentially be corrupted if there is extreme levels of cheating with collusion from the graders, but it does make it much more difficult and in your example, they got caught.