Legal Question in Real Estate Law in California

Based on the very limited information you provide, it sounds like he is owed more. How much more is the more difficult question. Unless he agreed at the time of the $30,000 pay out that it was all he would get, he's entitled to have you honor the deal you made in the divorce. The complication is that he got 13 years of the value of $30,000 early and you paid mortgage interest on it. So it doesn't sound like he is entitled to half the equity on sale minus $30,000. It should be something less than that. A time value of money calculator suggests receiving the $30,000 thirteen years early was worth $20,000 to $25,000. Without knowing your mortgage interest rate I can't calculate what you paid on the $30.000 but if you refinanced at the average rate in 2009 your interest expense on the $30,000 would be in the $11,000 to $14,000 range. Bear in mind these are just guestimates, but it sounds like what he is owed is half the equity upon sale less about $60,000 to $75,000.