Conundrum...buying house from recently disabled family member

[Lynne Marquez]

recently a family member found out he had diabetes the worst way...passed out and woke up in the hospital minus 1/2 of his foot and a toe was also amputated on the other foot. He has not been able to work and has had a tough time making his mortgage payment. He has been in his house 10 years. he has been relying on family to pull him through. After listening to the bigger pockets podcast I made him the following offer:

His purchase price: 80,000 (after 10 years he still owes 72,000)

I am offering to buy his home for $100,000. I will put down 20% ($14,400). He will pay closing costs. Once the deal is done, he will return my down payment and have roughly $10g in his pocket. he will then begin paying me rent for $550-600 a month (mortgage payment plus $100 toward any repairs), property taxes and insurance will be in escrow. That will give me my first deal with essentially no money down, and give him $10g to hold himself over until he can get back on his feet...no pun intended :) His mortgage is currently $900 per month. Am I missing something or is this a win, win? I just want to make sure I'm not overlooking anything. Any advice would be greatly appreciated.