CanaryJohn could simply prove with a statement from his bank or e-wallet provider that he really may not have received the payment. If he isn't able or willing to do one must assume that he has received the payment. There are not much possibilities or explanations to proove except: Statement Ultra Partners (obviously already done ), statement of payment processor (?) and bank or e-wallet statement from CJ (?) Hope that this can be solve somehow for all parties and not become a shame for anyone.