@OP anything you stole wheter it is have amount or not aslong as it's not yours well it can be also called stealing and that qct is strongly prohibited by law since this doing is illegal act by those people who cannot do good deeds to people and want easy money on their pocket.
It's obvious that all bitcoin transaction are recorded in the blockchain and that is a basic knowledge.
But anyways it's not the OP concern. The coins are mistakenly received by it's new generated address and I think it's just fine if OP will use it since it's all accident and no such thing as reversible in bitcoin transaction.
That is what I am telling him that the transaction are recorded and can be trace if what bitcoin address it will go to,
Well if the case that it is just a generated address and has a bitcoin in it that he doesn't know if who's bitcoin it is well he can surely get a grip of that coins, maybe it is not a crime because he got access on a free address that has a bitcoin but it is not through your hardship so I think it is free bitcoin so he can take it without further adieu.