Clarification of a Pandemic rule involving the Medic
I hadn't thought about it before, but the English rules could probably have been written a bit more precisely as well. However, your final interpretation is correct, i.e. cubes are only removed from the city the Medic is in.

From page 5 of the rules:


  if the Medic at any time ﬁnds herself in a city that contains cubes of a disease that has been cured, she may immediately remove all of those cubes.


"Those cubes" would refer only to the cubes in the city she is in.