That's a good compromise. It's a windfall for sure. I guess the only nit is that what is it that contractors USUALLY find on projects....problems! I would share the wealth because it's the right thing to do, but I'll bet if he found wood rot instead of boxes of cash, that problem would be all mine to solve, wouldn't it? So, we share the windfall, but we don't share the risk. If it goes to court (it won't), the contractor would lose on the grounds that there is no consideration. (all upside, not trade, and no downside)