So many things in this thread that make no sense to me. The guy is a minority share holder and acting in good faith, this is a completely different situation than a sole proprietorship with outright fraud.
These things are not related.
Thomas' advice may sound harsh but it is absolutely the most realistic approach here, he has to think about #1 for a bit and divorce himself from identifying corporate debt with private debt. He technically doesn't owe anybody anything as far as I can see and by assuming responsibility might actually make matters worse (because he is now at least acting as a signing officer of the company).
No, it isn't harsh at all, but I think that to people that have never been on or over the edge that it may sound harsh.
I had a stake in a Canadian gas station, the lady that ran it had signed up for some stupid carpet cleaning machine that they were paying through the nose for. She was complaining about how much it had cost and how many years they would still be under contract, it would have cost about 50 times what the p.o.s. was worth.
So I asked for permission to negotiate a solution, received it and called the company. I presented them with two options, $100 to buy out the contract (and keep the machine) or a very protracted collection procedure with 0 chance of success and a very large amount of bad publicity. The one phone call was all it took.
Business is not always being nice, and in this case the OP is being way too nice and is not looking out for his own interests as much as he should. The fact that his co-founder left him to rot is particularly galling.
Oh, and I think you meant 'wouldn't', not 'would'.
These things are not related.
Thomas' advice may sound harsh but it is absolutely the most realistic approach here, he has to think about #1 for a bit and divorce himself from identifying corporate debt with private debt. He technically doesn't owe anybody anything as far as I can see and by assuming responsibility might actually make matters worse (because he is now at least acting as a signing officer of the company).