I can tell you from experience as a Professor - I see it all the time - it may be conflicting to think about it, but the institution’s policy defines a Dean’s List award by year, not by overall performance. Besides, students do stupid things sometimes out of desperation which doesn’t necessarily reflect on their ability and overall performance during their tenure at the University… their integrity will be questioned… professors will be more watchful of them, but won’t deny any recognition that they are deserving of.