Well, the EV dial on many models changes one of the 3 values of the system. The value I've sen altered for all cameras I have owned is ISO, not Av or Tv. In fact, my Minolta has no EV dial, and the manual says for EV compensation shot-by-shot, change the ISO instead.
The point is, exposure will be changed no matter which of the variables is used. If you use a higher or lower ISO the camera will use either a faster/slower speed or larger/smaller f stop. It's the way it is and shall always be. =)