Venmo Scam? Help! I received payment for a product from an unrelated venmo account. Scam?

A person sold a laptop on Facebook Marketplace and received a Venmo payment from an unrelated account. The buyer claimed the payment was accidentally sent due to a cracked phone, but the Venmo account owner (Person B) denied involvement and refused to provide proof, leading to suspicions of a stolen account. The buyer later demanded a refund and threatened police involvement.