Not quite. Someone builds a separate private chain with enough hashpower to ensure it will ultimately be longer than our current public one. They send a transaction from our current chain to an exchange, dump it and withdraw the BTC. Once it's all said and done they unload their longer, private chain onto the network which doesn't have the original deposit so it's as if it never happened and they keep their NOBL. They've already received their BTC, so by that time it's too late to protect the exchange. All the orphans are a result of our current public chain being overwritten by the privately built one when it's unloaded on to the network.