The C of G would not change dramatically enough to cause the aircraft to be uncontrollable. Full forward stick would be enough to ensure the glide is at a proper speed.
The rpm of the engine is "controlled" by the pitch of the prop - so no prop will mean an over revving motor. At normal throttle settings with no prop (ie no resistance) the revs would run away until the motor seized ot the throttle was pulled back.
I would guess that the fatalities were the result of un unfortunate forced landing (probably with limited visability) and not due to an uncontrollable aircraft.
I am an owner of a C210 so let me know if you would like me to get the POH and do an accurate calculation of the C of G.