Worth noting, even if the material does not end up with full-on superconducting properties, it could easily still represent advancement in the field. One way or another, it does appear to be unusual.
I can pretty easily see someone getting excited about the prospect, being afraid of getting scooped somehow, and so rushing to publish to lock in their fame before all the necessary work has been done. A little unethical, but certainly understandable. And even if mistaken, it’s still another step in the scientific process.