So Apple is saying that syncing to iCloud is a backdoor.
I mean, they are proclaiming to the world that they really want to protect their users privacy and make secure devices, but at the same time acknowledging that the data backed up in the cloud is accessible to their engineers.
The phone in question was a work phone, not a personal phone. In work environments the enterprise IT tools control how the phone is administered, backed up, and the like. Which means that the company that issued the phone most likely had the key to unlock the backups.