Hi MM,
I don't know all the details but to me it sounds like this RE deal is a big part of the business that you want to be 50% owner of (or 49%, not sure)and to me, I would think it affects you as much as him. At least money and the future of the business wise. If you are a 'partner" shouldn't you be a part of deciding if the business should buy this property? Buying from a "crack head" seems risky to me. It may be the property HE wants but if you can't be sure the seller is being honest it may be time to look at another. Is this property for the business or for him? If it's more for him, how would it affect the business if something bad happened and he lost a lot money due to the seller being a crack head? Would the money come out of HIS pocket or would the business (and if you are a partner, that includes you!)take the loss making the business worth a lot less and causing YOU a big liability?

Don't let the personal stuff get in the way of the business stuff. Think of him now as just a business partner and would you want a partner of yours to do something that puts the business at risk? MLCers are very bad at thinking things through correctly. They tend to do things that don't make sense because it's what they "want" at the moment. They don't think about people that they have loved for decades, how do you think they feel about someone who is "just" a business partner (and that is all you are in his mind, at least for now).

I guess what I'm getting at is make sure his actions don't only hurt you personally but also hurt you by hurting the business you helped build because he has poor judgement.