I have a contractor that asked for two milestone payments. Even though one of them was a little early (not 100% completed but close) I agreed to pay both of them but because I have in writing that I will agree to pay him both payments even though one is a little early, he is holding the (smaller) payment and not depositing it. Even though he insists neither of the payments are early. Is this some sort of strange strategy to avoid legally being found to accept an early payment for work not done yet? I think him not depositing the check is almost an admission of the payment being early but am I missing something?