I think that punishment is stupid. Why would you take xp away from other skills? Yes, yes punishment bullshit. Just take away xp from the macroed skill and ban them from doing that skill for a certain amount of time. That seems much more logical and fair to me. Now if people get caught a second time, do whatever you want to them because you are dumb if you get caught twice.
A punishment is not designed to be nice. Twisti: 10 million XP is approximately 20% of his whittling XP. It is a very significant amount.