It is referring to the transformation of a blackhole into a whitehole (which, of course is not possible within our iteration of a universe). The force of the whitehole would overpower the force of gravity, seeing as gravity is on the weaker end of the fundamental forces of nature.
I'm surprised I haven't heard of virtual particles before this...though I have heard of blackholes evaporating. Is it known what causes them to form, or is it more of a theoretical thing to help explain the evaporation?