Steve... legalities aside... do you think you will be able to work with Joseph in the future?  What he did would certainly damage any relationship, so, from the heart... do you think this situation is fixable at this point?  I would imagine your first inclination would be to say, its up to him... however in reality its up to you also as to how you would receive any concessions, if there were to be any.  Has his actions to date reached a level, or point, of no return?

You two seemed, by all outward appearances, to have a good working relationship prior to this issue.  Evidence of such would be the progress and achievements the company has made since the purchase.  You two seemed to make a good team.