Apple already has a backdoor key which they use every single time any iOS device needs to update. The FBI wasn't asking for the key, they were asking for the ke

Apple already has a backdoor key which they use every single time any iOS device needs to update. The FBI wasn't asking for the key, they were asking for the key to be used to sign one update. That signature would inherently have only worked once, as it includes a nonce and device ID.