He has NO point. He has no right to mouth you off like this. Take a cue from The Social Network.
[leans down close to Mark, his voice low and dangerous]
And I'll bet what you hated the most was that they
identified me as a co-founder of Facebook, which I am.
You better lawyer up asshole, because I'm not coming
back for 30%, I'm coming back for EVERYTHING.
[backs away from Mark slowly, still looking at him]
Hint, that is what you should be getting ready to do. If he runs his mouth like this again, fire his ass, he's trying to snake his way in.
I think The Social Network is a bad example. I don't know what happened in real life, but in the movie the guy was never there. I wouldn't want an absentee co-founder to have 30% of my company (or even 5% for that matter) either if I was working on it full time.