[spinny]

what is tracked is outputs and inputs, not addresses. addresses are derived from a public key or a script.

when a block is mined, an output is created, outputs can only be spent once. a bitcoin transaction is just a list of existing outputs (inputs) and new outputs to create (outputs). each output is created with a lock script, to spend the output you must provide the unlock script which normally contains at least a signature and a public key

returning the output that corresponds to the unwanted transaction should do

[thinkmassive]

Would you pay the transaction fee from the returned funds, washing a fraction of it through mining? Or pay for it out of your own utxo, potentially leading to a griefing attack?