The argument was about, Is it possible to recover any digital currency like Bitcoins and others after sending it to a wrong address ?
It is not possible to reverse a Bitcoin transaction that has been confirmed, and even if the sender wants to recover it he/she won't be able to do that. Because all the transactions that are made with Bitcoin are truly decentralized and are irreversible. There have been some cases where some set very high transaction fees that miners have returned, and even the same happened with many people who mistakenly sent higher amount in transaction to an address which were returned back to the original sender.
In your case only the one who received the Bitcoin or any other irreversible crypto-curranty has the power to send you those coins again. Other than that there isn't a way to get those coins, and even if you know hacking, you still won't be able to get those coins back.
There are some crypto-currencies that allow reversible transactions such as USDT, XRP, XLM, and some other crypto currencies also have some level of support to reverse a transaction. However, that's not an easy thing to do, and even if the transaction was made with any of those crypto-currencies, you would still won't be able to receive the money back because they don't have that much time to reverse simple and low amount transactions. In some of those coins the network of users collectively have to decide whether they want to freeze or reverse a transaction or not.