If they are correct, they will have discovered a new form of nuclear decay, and given scientists a powerful way of investigating the structure of the nucleus.
Radioactive nuclei are unstable by nature, and they perform all kinds of tricks to settle down.
In some cases, a nucleus may wish to spit out two protons. There are several ways physicists imagine this can happen. The helium-2 nucleus then splits into two separate protons. Neon-18 cannot emit one proton at a time, because it's forbidden by quantum theory. But it can lose two protons at a time.