If the optical connector on the OASYS is anything like that on the Kronos, then the conector door is not part of the retention mechanism. A firm pull outwards on the connector body should be sufficient to remove it.
It's just like the Kronos, and you're right. You just have to be careful since this is how I broke the door on my first Oasys. I thought there might be a trick or something to reduce the risk. I probably just pulled it sideways instead of straight out. Thanks for your reply I'm glad to have this confirmed.