The reality is, there has to be. And, if you can't trust someone then don't work with them.
I was talking to an amazing lawyer/business person I know one day and I asked about writing 'air tight' contracts which would never put you in a position to be screwed. He said something along the lines of, that's impossible. Someone could take you to court and you could still lose even if you think the contract is perfect. What he said next stuck with me over the rest of my career, 'if you truly can't trust someone, no contract will be fool-proof. The solution is simply to not work with or do business with them.'
Huh? Do FBI/CIA/etc run that way?