Can a scammer reverse a bank transfer?

Could you please clarify for me if it's possible for a scammer to reverse a bank transfer once it's been completed? I've heard mixed opinions on this and I'm wondering if there's a definitive answer. As someone who deals with cryptocurrency and finance, I'm particularly interested in understanding the security measures in place to prevent fraudulent activities like this. Is there a specific protocol that banks follow to prevent scammers from reversing transfers, or is it more of a case-by-case basis? Thank you for your time and expertise.