That scam relies on the purchaser sending the full payment almost as soon as the bank transfer details have been sent to them, otherwise they’ll see the legit details too.

When I’ve bought residential property in the past, there have always been various fees to pay in advance, using the same bank details. So when it comes to the final big payment, I’ll have already had the bank details for weeks, and have already used them to send previous payments. Double checking the payment instructions by phone just before making the payment helps too, as that allows confirming the account and the final amount.