Creative use of mechanic, or exploit

[Vyndree]

In any case folks can still go to zolo and fight him just like they did before the last patch, so THAT wouldn't be exploiting. (although who would want to?).

Correct. The exploit wasn't the way it was done -- it was the end results achieved (XP).

If you were to find a new way to get the same XP out of Zolo, as was done pre-patch, that would be the exploit. I'm not saying killing (or grinding) Zolo was the exploit -- but the massive amount of XP gained for the minor amount of effort (I hear many people claiming the important part to Zolo is jumping often so that your other characters don't go AFK). Don't pick on semantics -- you know I've never had a problem with Zolo pre-nerf, but just post-nerf the same result should not be achievable without expecting retribution from blizzard. Nobody did Zolo in that fashion "just because I wanted to see the encounter". They did it because of the massive amount of XP gained.

The exploit of Zolo was the advantage of XP per hour per effort. Not the encounter itself.