Right, at that point we're getting into semantics. If the votes aren't counted correctly, and a group of people are doing it somewhat systematically, I consider that fraud. Given that they were students (and the overall result did not change dramatically), judges were lenient and basically said "mistakes happen, no hard feelings".
I have little doubt that it would have been quite different, had the situation been reversed, but I don't care enough to argue about it with you.
Man, courts mandated a full recount. The only mistake they found was 13 missing votes. Which the court deemed to be within expected margins (don't ask me, I have zero experience with that). The result was a lost seat for the AfD, and an election deemed legitimate. So no fraud whatsoever.
And no, I have zero doubt the judges would have enforced a result that gave the AfD a seat at the expense of another party, if that was what the recounted result said. Only that it didn't.
This was a legal question, one that was answered. What you or I deem fraud or not became irrelevant at that point.
I have little doubt that it would have been quite different, had the situation been reversed, but I don't care enough to argue about it with you.