The paper states the following "particles become energized over a limited volume, for example at a shock front, and then advect or diffuse away from that region" which indicates these particles are energised before entering the event horizon so it doesn't appear to be a process that occurs within the EV. Nothing is being "ejected", it's being forced away.

The theory here is a shockwave caused by a "magnetic reconnection, where magnetic field lines break, reform and connect with other nearby lines", which is the same process that accelerates plasma on our own Sun. There's nothing to specify these particles were "orbiting" anything. But yes, it does appear to suggest that these particles did not enter the black hole before entering the "jet" and being expelled.