If the transaction is complete and you have received the Bitcoin in your wallet then he can't withdraw the Bitcoin from your account. If that person asks you for your seed phrase or private key then never share those details with him or anyone else because he or anyone else will only be able to withdraw that Bitcoin from your wallet if they have the seed phrase and private key of your wallet otherwise they it's transferable by anyone other then you. I think you got enough answers on your thread and that's why it's better to lock this thread now.