When I accidentally drilled holes with the wrong hole saw, I used a scrap piece of metal to cover the area of both holes and JB welded it. Then, I just re-drilled the holes with the correct bit. After painting it looked alright....helped that my mistake was underneath though, rather than on the front.
Check out my thread on "Mistakes I made while building Kals electric brewery"
And now you see that Evil will always triumph, because Good is dumb!