The biggest problem you have is that your situation is wholly unresolved -- it is unclear who owns what and who owes what -- if he was merely angry, I assume you could live with that.
Clearly you have broken up your partnership. But how have you divided assests and liabilities? It seems as if what you did was take the business, which presumably then had, and has, value. Exactly what that value was worth is the issue. And a second issue is what share did you each own in the business? If he owned half and you owned half (although you carried it in your name) each of you would, on dissolution of the partnership get to keep 1/2 the value and be obliged to pay 1/2 of the liabilities. Here you took all the value and feel upset that you are left with all the liabilities. But why should you get the assets and he get the debts? It may be that the business (including its assets and GOODWILL) was worth $1,000 and the debts were $20,000 in which case the exchange would have been unfair.
The major danger you face is that he could claim the value you took was worth $100,000 and there were only $20,000 of debts and now he asks for $40,000.
I'd urge YOU to speak with a business lawyer and get professional advice and an agreement drawn up and signed that ends this once and for all.
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