I would disagree- paper towels are the substrate of choice with a new snake that might have mites, at least until you're sure they don't. Also, white paper towels show other serious issues too, like a mucoid or bloody smear from the cloaca, or diarrhea.![]()
This one was the smallest of the clutch-mates too- making it a bit more likely that something else didn't develop quite as well as the others.
Ideally though, a necropsy "might" have given an answer, & someone wanting a refund or exchange should NOT have discarded the body before checking with the breeder, IMO. That they did adds room for some doubt as to their handling or "ideal conditions".
Failure to thrive has been known to happen after not just a few weeks but even months. It all depends what the issue was.