Slattery has defended himself by saying that his work was meant to be a "cynical hoax", and also that it was really done in the Cento form, a work composed of verses taken from other authors but reworked into a new form. Of course there is no attempt, as is critical in Cento, to credit the original authors, many of whom are still writing work that is under copyright. It may be the case that both Slattery and Nunn have been attending classes by Kenneth Goldsmith, who is a strong proponent of "Uncreative Writing". Goldsmith teaches his students that "How I make my way through this thicket of information—how I manage it, parse it, organize and distribute it—is what distinguishes my writing from yours." In other words, you can and should 'help yourself' and work with what's already out there.
Repurposing is all fine and well and there have been some wonderful, startlingly original works of art that have come from the sampling process (some of it is Goldsmith's), but taking someone else's original, carefully wrought words and presenting them, sometimes to contest judges, as your own carefully wrought words, with no credit, no permission, and no indication that this is what you're doing is just theft, pure and simple. There's no euphemism or explanation that can make this kind of theft okay. All writers have felt a hint of jealousy when reading something that is so perfectly written that we wish we'd written it ourselves. It doesn't honour other writers to pretend that, nor does it do yourself any justice - since I'm sure both Slattery and Nunn are fully capable of writing their own exquitely unique verses - unique because it comes from their own unique perspective and talent. What this kind of serial plagiarism does is to denegrate writers everywhere by diminishing and devaluing the hours and hours of hard work and personal internal mining that is an integral part of the writing process. By all means, borrow, repurpose, re-create, but do it with credit, permission, and above all, with honesty and honour. Otherwise it's wrong, pure and simple.