I'm not defending Lazar in anyway but saying that a single isotope of element 115 fizzles out quickly does not mean that all of its isotopes behave the same way. It's been long predicted to have an isotope in the island of stability, it's just a very difficult and expensive to create the isotopes. Beyond being the first to create it, it's difficult to justify spending millions of dollars to track down other isotopes.
The super dense asteroids they found are 3-4x denser than the densest material we know about (osmium). Roughly 80g/cm3 vs osmiums 23gcm3 so even if the measurements are off by 50% you're still looking at something we can't explain. There are lots of weird objects that defy our understanding all over our solar system, many within reach of probes we can already build. Dense asteroids, weird unexplainable orbits, ones that spin so fast they should tear themselves apart but don't. It's sad they don't mass produce a singular design and take a peek at a bunch of them.