I think it is just regular momentum that is conserved here. Of course, the difference in mass between the jumper and the earth means the change in velocity will be much more noticable for the jumper than the earth.
I think this was at San Joaquin Delta Junior College. The roofing style and wall paint color, even the circular air vent. It looks virtually the same. And this being Stockton, same home to the Fat Kid Stuck Like Pooh In A Manhole, I'm not that surprised.