Mcflainthegreat

So I just stumbled on this what seems to be an exploit. I was doing the Kanto E4 where I finally beaten lance but I was not ready for Gary in which I lost. But the thing is, when I replayed the E4, I still gained exp and I thought that this was fine so I continued to use the exploit to lvl up my gengar to lvl 100, I also intentionally lose to gary to keep farming the exp. When I told others about this, they told me that this was not intentional and probably an exploit. I am sorry, I didn't knew this was an exploit and I discovered it by accident.