Denmark’s leading anti-piracy group is shifting to a more aggressive litigation strategy.

Unless the students are acting incredibly naive, it’s almost impossible for the anti-piracy group to lift the burden of proof here.
In general all you have to do is to claim you know nothing about it. For instance having “evidence” that your IP address was used for download is not enough.

Also the Anti Piracy group has a reputation of themselves working outside the law here, so maybe an investigation into this group could be a good idea.

da.wikipedia.org/wiki/Johan_Schlüter

Johan Schlüter was for many years the embodiment of anti piracy in Denmark forming “AntiPirat Gruppen” (Anti Piracy Group).

I 2014 idømte en fransk domstol ham 18 måneders ubetinget fængsel

Translation: In 2014 a French court gave him 18 months UNCONDITIONAL prison term!
The case was followed up with a $5 million lawsuit. For the fraudulent handling of Charles Trenet copyrights.

In 2015 he was reported to police for defrauding 100 million from copyright holders. The investigation found “inconsistencies” in 4 companies owned by Johan Schlüter. Later that year AntiPirat Gruppen" was declared bankrupt.

i juni 2017 tiltale mod Schlüter og to andre advokater i Schlüters advokatfirma.

In July 2017 cases were raised against Schlüter and 2 other lawyers in the company.

So the people handling these copyright investigations and cases do not have the best reputation. In fact they are the real thieves stealing from copyright holders, embezzling their money through their judicial con job. Promising to help, but doing more harm than good, to a degree that Denmark is now basically protected against anti piracy lawyers immoral and illegal activities.