According to the records written down during the negotiation that remains today, the negotiation was entirely in the hands of Parkes from start to finish, and he confronted the government with evidence indicating the fact that the Meiji Government coined bad money violating the kaizeiyakusho, and that domains coined counterfeit money (according to a part of the records, Parkes became worked up over an answer by the government which was off the point, and hit and broke a cup near him).
現在残されている談判に記した記録によれば、談判は終始パークスの独断場であり、明治政府が改税約書違反の悪貨を鋳造し、諸藩が贋貨を鋳造していたとする事実を示す証拠を次々と突きつけていった（一部記録によると政府側の要領を得ない回答に興奮して、傍にあったコップを叩き割ってしまったとされている）。