Bob says to Rob: "I offer you $1,000 for this thing".
Rob replies: "I accept your offer".
From this very moment, is Bob the legal owner of the thing? Or does he need to wait for the occurrence of payment, payment clearance or delivery before he becomes the owner?
Bob and Rob are both private individuals who do not know each other other than for this transaction. Rob is not a store, he is just a one-off seller of the only thing (which he owns). There is no written agreement.
In the united-states, the parties are generally free to agree to a different rule, but by default, the rule under UCC Article 2-401 is that:
title passes to the buyer at the time and place at which the seller completes his performance with reference to the physical delivery of the goods.
It is therefore not clear whether Bob is the legal owner of the thing yet. If this transaction unfolds at Rob's garage sale, and Bob is already holding the goods, it seems unlikely Rob as any futher delivery obligations, so the title has likely transferred.
But if Bob is replying to Rob's listing of This Thing on Facebook Marketplace for $1,000 with an offer to deliver it to the buyer, then title would not transfer until Rob makes delivery.
