No tricks. Some people are under the misconception that embryonic stem cells are harvested from aborted fetuses (Matt Stone and Trey Parker seem to believe this). You apparently know better, so I have no argument with you.
Dr. Gearhart does harvest embryonic germ cells from aborted fetuses because these germ cells have not yet left the embryonic totipotent stage to begin the long process of gametogenesis. His goal, mainly, is to derive ova for conceiving embryos for experimentation and to study potentials for parthenotes, but his research is delving into other 'pathways of differentiation' issues. So yes, there are embryonic stem cells being harvested from fetuses with Gearhart and his colleagues.
Some people are right. It depends on the experiment. One group at our University uses cells harvested from 14 - 20 week old fetuses, obtained from a local abortionist.