Just because the content wasn't available for purchase doesn't mean it wasn't copyrighted. I am not familiar with UK law and am open to correction, but it sounds like this was still illegal. Not that I think it's such a bad thing, but "Legality is no defense" is just linkbait.
The title doesn't match the story. UKNova's policy may be morally good and "respectful" of copyright holders, but what it isn't is legal; just because the DVDs won't be out for another 15 days doesn't mean you have a license to distribute a copyrighted TV show.