What he did was a physical assault. It was premeditated and he was the main instigator of his crew of bullies and didn't stop until he'd terrorized that young man who didn't deserve any of that. I'm glad you repented as you did it, and are the better man for it.
If Mittens had been half the man you are, he would have stopped in the midst of harming Lauber. Mittens did not and will not admit he did anything wrong, but you did. You repented, he laughed it off and profited by it. He went on to destroy the lives of others for years.
That most of you quit, says there was a change of heart and that you remember it as a shameful thing, says much more than Mittens every will.
While making this reply, I remembered something. I've always hated bullies. The last day of elementary school I was walking with a crowd of kids, beside a girl I didn't know well. Some boy ran up and knocked her things out of her hands. That was one thing, I reached down and picked them up. But when she started to cry, he started to laugh. And I was livid.
The next moments are not really clear, but I gave him a knuckle sandwich. When he fell down, he started crying. The other boys ran to me and cheered, 'You did it! You beat the school bully! Wow!' or something to that effect. Then he got up and we all kept on walking and I forgot about it. I didn't apologize and neither did he.
I didn't know his reputation, but he was not going to do something like that in front of me, make someone cry and then laugh. I'm not proud of hitting him, but it ended with that incident. When I think back, he was probably beaten at home and carrying on the pattern.
So this many years later, I don't feel good about it, although I didn't feel any pride at the time, either. As an adult we see things differently. I'm sure Mittens never paid for his antics.