I'm not sure that I agree about either of those things.
You said that it may have been you, or it may have been Mikey and that it was something that you did together. Not Alex is saying that the edit (which only a small number of people get privvy to do) was made when you were all home alone, which means that it was likely definitively you, although I haven't seen any ownership over that. The consequence is a little secondary here. If I was taking steroids to get jacked and impress the chicks, but a by product of that was that I also became the world 100 metre record holder, I wouldn't be able to get out of the 'cheating' scandal by saying that my intention was not the end result.
I would also say that the punishment is something that should be discussed too. I'm not comfortable with the idea of the person who was caught cheating (or however we want to present this) is also the one that sets his own punishment. That would move this from silly high jinx of making a alteration as a 'jokey' fuck you to me, or to gain an advantage down the line for yourself (or for whatever whacky reason it was) to FIFA levels of cover-up style corruption.
Is that who we want to be? Should I be expecting an offer of hush money?
I'm not saying that I disagree with your self-imposed punishment, I just think that it's totally wrong that you should be the one who decides on it.